The Mother-Fucking Side-Effect Pt. 03

A week had passed since the events in the backyard, and Friday morning found Hal once again sitting in the kitchen sipping his coffee. Carol had taken a phone call nearly 20 minutes ago and was still in the den having a hushed, but seemingly serious, conversation with someone. Gavin had finished breakfast just a few minutes earlier and had gone upstairs to take his medication for the day, leaving Hal alone with his thoughts.

And there was plenty for him to think about. It had been ten days since he'd arrived home to find Gavin, he and Carol's 18-year-old son, grudge-fucking her in the living room. The apparent dual-betrayal had in reality been nothing more than the unusual side-effect of a depression medication Gavin had just started on. The meds, shortly after ingestion, turned him into a sex-crazed animal of a man who would fuck anyone he pleases, including his own mother. Then as now, Carol saw it as her parental duty to usher their son through this pesky side-effect, and every day since had been sating his hyper-virile desires with intense sex "sessions" that could run as long as eight hours.

At the end of these sessions, Gavin would slowly revert to his normal self with no memory of what (or whom) he'd done. That was well-enough for Hal and Carol, who had early on decided to shoulder the responsibility for both managing their son's hyper-virility and of keeping the secret of how from him.

In fairness, Hal really didn't do any of the heavy lifting when it came to handling Gavin. It was Carol who would fuck him for hours on end, and Hal's task was generally just to listen without going insane. That had become somewhat easier for him over the past week, as the sound of his wife getting plowed by their son and his monster cock had become so common it barely even registered for him anymore. If anything, though he'd never admit it to her, listening to Carol's moans and grunts and frequent screaming orgasms was becoming a major turn-on for Hal.

That part was a bit troublesome, though, as Hal and Carol's own sex life was still majorly disrupted by her "helping" Gavin. Fucking their son had become like a job to her, meaning she had very little left in the tank for her husband. They'd fucked only once in the past ten days; a quick affair that had ended with Hal blowing his load long before Carol had any chance to have an orgasm of her own. Hal could hardly feel guilty about that, though, considering the frequency and intensity of the orgasms she was getting from Gavin's beefy dick.

In the other room, Carol could be heard wrapping up her phone call. Moments later, she returned to the kitchen, a concerned look on her face.

"Did Gavin go up?" she asked, looking around for him.

"A few minutes ago," said Hal.

Carol sat down at the kitchen table where her oatmeal was now sitting cold.

"That was Brenda. Apparently, after Gavin and I left there yesterday, she fell asleep without cleaning herself up. When Teddy got home, he saw all the cum on her and assumed she had cheated on him with a group of guys. He was only partially wrong, of course," said Carol, taking a bite of cold oats.

In the week since the incident in the backyard, Gavin and Carol had gone back to Brenda's several times so that she could "help" with Gavin's side-effect. It had offered Carol a bit of welcome respite from handling their son's daily sessions solo.

"Damn, sorry to hear," said Hal.

"I think they'll work through it," she said with a little frown, "selfishly, I'll miss having an extra hand with Gavin, though I won't miss some of the things he tried to make us do."

Hal nodded knowingly. Carol had not given him nearly as many details about the sessions at Brenda's as he'd have liked, but she had shared that, at Gavin's insistence, she and Brenda had done a few "girl-on-girl things" with each other. Some kissing, touching, and even some pussy-eating, all of which Hal would've paid good money to see.

Carol finished her oatmeal and brought her bowl to the sink.

"I better get up there before he comes down and bends me over the table again," said Carol, heading for the stairs. Hal was continually struck by the content of the conversations between him and his wife these days.

"Do your best to keep it quick, remember I need him to help with my mom later," said Hal. Hal's mom, Lorraine, was moving out of her house and into an apartment that afternoon, and Hal had taken the day off work to help, along with Gavin.

Carol simply nodded in response and left the room. Hal knew there was only so much she could do, but as long as the session didn't take much more than four hours (the current average) they'd be able to make it to his mom's in time.

Hal moved to the couch to kill some time scrolling on his phone. Within minutes, the sound of Gavin's headboard thumping rhythmically against the wall signaled that he and Carol had started their session.

"Hm," mumbled Hal with a quizzical look. Usually Carol started by blowing Gavin, but by the rocking noises of the bed they'd skipped right to fucking. Gavin must be in a mood, thought Hal.

In short order, pleasured moans (mostly Carol's) and even the muted slapping of skin on skin joined the thumping of the headboard to create the soundtrack of incestous fucking that had filled the house for over a week, now. Hal had grown used to the sounds. In a way he wouldn't admit but couldn't ignore, he had even grown to enjoy them. He knew he should feel shame or anger or any number of other earned emotions, but the truth was that his dick was hard for most of the morning just from listening to his wild stallion of a son shtupping his sexy wife.

With all the fucking happening in his proximity lately, Hal's own libido had skyrocketed. He only made it half an hour or so of listening before, inadvertently, he was rubbing his own throbbing erection through his jeans. His mind was conjuring images of Gavin's thick meat-pole buried in his wife's cunt. He could hear Carol's moans, little yelps and squeals, and he was powerless to resist.

Hal sat on the couch and unzipped, wrapping his fist around his hard-on and stroking it. He pictured Gavin's sweaty ass pumping away, Carol's big tits bouncing. He jerked faster, picturing Carol's face, the little grunts and groans she made when she was close. He imagined Gavin slamming his hips into her, his balls slapping against her asshole, and Hal groaned. He closed his eyes and imagined it was him up there, fucking his wife senseless with a cock that was half again as big as the one he was currently holding.

Hal wondered, in passing, for about the thousandth time in two weeks just where in the hell Gavin had inherited that huge slab of cock from. Intermingling jealousy and pride wrestled inside Hal, both happy to know his son was hung like a donkey and irritated that he, himself, was not.

"It sure as shit didn't come from my side of the family," Hal thought, picturing his own unremarkable cock. Were Carol's family, his in-laws, all hung like goddamn Clydesdales? He thought about Carol's dad, a hard-ass named Frank, and her pervy brother, Tony. Those two were pretty big pricks themselves, maybe their actual pricks matched their personalities? Maybe Carol would know; she had grown up in the same house as those two.

The sound of Carol screaming, rather loudly, through an orgasm brought Hal back to the moment. He listened to his wife's climax, quickening his pace before quickly going over the edge himself and spraying a few steaming ropes of cum onto his t-shirt. He didn't care about the shirt; he'd toss it in the wash and it'd be clean hours before his wife and son were done fucking.

The sounds of sex from upstairs continued on for hours: loud yelps and moans from Carol, sharp smacks of skin on skin, and the ever-present rocking of the bed frame. Periodically, an animalistic growl from Gavin would indicate that he was dumping a load on or in his mother. Those would sometimes be followed by a brief respite of quiet before the cacophony would inevitably begin again.

But as noon passed Hal began to worry about time. There wasn't much left before he and Gavin were meant to pick up Lorraine, and based on the sounds upstairs Carol and Gavin weren't even close to finishing.

Begrudgingly, Hal got up to go check on them and hopefully press Carol to wrap things up. The sounds of sex grew louder as he walked up the steps and down the hall to Gavin's room, pausing for a moment outside his door. THWAP THWAP THWAP was the predominant noise from inside, a wet slapping of bare flesh. Hal knocked softly but, predictably, heard no response.

Opening the door, Hal was met with the smell of sex and stale sweat. Poking his head in, he saw Gavin standing at the foot of the bed, facing slightly away from him. He was completely naked, his smooth, sweaty skin stretched tight over his lean muscles. He was throwing his hips hard into Carol, who was on her hands and knees on the bed, receiving his intense doggy-style pounding. Her big, heavy boobs swung under her in time with his thrusts, as did his smooth, kiwi-size balls as they slapped against her thighs and clit. He had a hand twisted up in her hair, pulling her head back as he held her by the reins. Her face was flushed a deep red, a contorted look of unceasing pleasure frozen on her face.

"Ungh! Ungh! UNGH!... Fuck!... FUCK!" moaned Carol, her voice stripped bare of any semblance of composure.

Each thrust of Gavin's lean hips brought a loud, meaty THWAP as they collided with Carol's bouncy ass, the sound echoing in the otherwise silent room. The force of the impact sent tremors through her body, her flesh rippling and quivering beneath his relentless pounding. Simultaneously, a distinct, obscene squish accompanied every in-and-out stroke of his fat cock, the sound of her soaking wet pussy clinging to his thick shaft.

Hal cleared his throat.

"Hon? Any chance of speeding things along? It's getting close to time," he said cautiously, not wanting to interrupt them too much.

Carol glanced over at him, taking a few long seconds to even comprehend what she was seeing through the fog of rapture. Realizing her husband was in the room talking to her, she shook her head slightly, getting Gavin to relinquish his grip on her hair, took a few breaths and looked back over at Hal.

"I know h-... honey. S-... sorry, I've tr-... tried everythi-... th... thing..." said Carol, struggling to keep her voice steady as Gavin continued fucking her. Carol seemed lost in thought (or maybe in pleasure) for a moment before adding, "Well, almost everyth-... thing."

Hal knew that she only had so much control over Gavin in his hyper-virile state. He certainly couldn't be reasoned with, only guided, gently, to more and bigger orgasms which would slowly wear down his sexual resolve.

"Anything you can do, I'd appreciate it," said Hal, a bulge growing in his jeans as he stared, transfixed, at the scene in front of him.

"Hang on-... Oh shit... oh SHIT... shitshitshit fuuuuuck..." Carol squealed.

She buried her head in a pillow for a long beat, biting it as the quaking of her legs and arms indicated that Gavin had pounded yet another orgasm out of her. For a long moment, she was lost in the throes of her climax, her world reduced to the raw, pulsing sensation of Gavin's cock buried deep inside her. When the tremors finally subsided, she slowly lifted her head, her face flushed and damp with sweat, her eyes glazed over with a mixture of exhaustion and satiation. Hal, watching from the doorway, noted the dark circles under her eyes, the slight tremble in her lips, the utter depletion etched across her features. She looked drained, wrung out, like a dishrag after a particularly vigorous scrubbing. Yet the hint of a blissful smile tugged at the corners of her lips.

"I was hoping to keep putting this off, but there is one more thing I can try," said Carol, still catching her breath, "Hal, can you bring that bottle of lube from our room?"

Gavin was still fucking her from behind and Hal was hesitant to stop watching, but pulled his eyes away and headed for the bedroom. He had retrieved the bottle of lube from Carol's nightstand before he had even really processed her request. Lube? What for? Even as he pretended not to understand, the thumping of his heart showed that he knew exactly how Carol intended to use it.

Hal returned to Gavin's room to find that nothing had changed; Gavin was still humping away and Carol was doing her best to take it. Seeing Hal, she reached her hand out for the bottle he carried, and somewhat awkwardly he stepped past Gavin to give it to her.

"This is going to sting," muttered Carol as she opened the bottle and carefully squirted a large dollop of lube onto two fingers.

Hal watched from the doorway as she reached those two fingers behind her, back between her rippling ass cheeks and into her crack as she smeared the slippery gel around her tight, knotted asshole.

Hal thought his dick might rip through his jeans as he watched his wife, still getting nailed in the pussy by their son, slip a glistening finger deep into her own ass. Then another. She pulled them out, applied more lube to them, then repeated the process, preparing her little hole for what was coming next.

"You want to fuck me in the ass, sweetie?" she asked sweetly, as though asking if he wanted another slice of pie, "You want to fuck Mommy's asshole?"

Hal winced. "Mommy" talk was one of the things Carol had learned was effective in directing Gavin's actions in this state. It was still a little weird for Hal to hear, but the hyper-virile version of Gavin seemed to love it.

In response to his mom's question, Gavin merely grunted and pulled back his hips, letting his long, thick log slip out of her messy pussy. Taking it in his hand, he pushed his hips forward, the blunt head of his cock now pressing and trying to find entry past her butthole.

"Slow, slowly, baby," said Carol, reaching a hand back to steady Gavin's hips, "Don't hurt Mommy."

It took a few moments for Carol's hole to accept the thick mushroom tip of Gavin's cock, but eventually it slipped inside, drawing a wince from her. Remarkably controlled, Gavin rocked his hips back and forth, slowing getting another inch, then two, of his massive cock up her butt. Carol was breathing hard, the experience neither easy nor particularly pleasurable... yet.

Somewhere in the back of his mind, Hal thought he probably ought to leave them be, but there was no way he was going to miss this. He'd done anal with Carol plenty of times over the years, but this was a whole other level. Gavin's cock was like a baseball bat and Hal was anxious to see how well his wife could swing it.

"That's it, baby. Give mommy all of that big dick in her ass," said Carol. Hal knew she was playing this up, for Gavin's sake.

It took a few more minutes of careful, measured entry before Gavin had worked three fourths of his cock, around 7 inches, into his Mom's ass. That seemed like enough for him to start a more purposeful rhythm sliding in and out of her and focus again on his own pleasure.

Carol was taking it like a champ, but Hal could see the strain on her face. He could hardly blame her; she was getting buggered by their son's beer can-thick cock, after all.

SMACK.

Gavin's palm came down hard against Carol's right asscheek, drawing a yip of pain from her.

SMACK.

He brought it down on her left cheek now, eliciting another yip that, this time, trailed off into a moan.

SMACK. One last hard spank to her right cheek and Gavin began bucking his hips in earnest, resuming the pace with which he'd been pounding her pussy earlier. Carol's asscheeks glowed red, but the sounds she was making now were definitely more of pleasure than pain.

"T-that's it, sweetie," she said through gritted teeth, "Fuck M-mommy's little ass."

Gavin really didn't need encouragement at that point, but Carol repeated the sentiment several times over the next few minutes as he anally fucked her. She had him slow, only once, to apply more lube, but they quickly resumed a fast, steady pace.

"NNNNGHHHHGODDD..." groaned Carol, her son's fat cock stretching her in ways she'd never been stretched, his full balls slapping against her wet pussy as he started bottoming out in her ass.

Gavin was grunting like a wild boar. Since the first day on the meds, he'd been trying to fuck Carol in the ass. Hal could practically see the beast behind Gavin's eyes howling in victory for finally fulfilling that desire.

It didn't take long (at least in comparison to their marathon sessions) for Gavin's hips to stutter and his rhythm to falter as his balls tightened, a major orgasm about to spill out of him. He buried his cock deep one last time, drawing a shriek from Carol, before pulling back to let it slide all the way out. Quickly taking it in his hand, Gavin pumped rapidly as blast after blast of sticky, white cum burst from his glistening cock. In seconds he had laid zig-zagging ropes of jizz all across her jiggling ass and down her back. Pools of the stuff collected in her ass crack and he sprayed down her slightly gaping asshole directly with a few thick globs.

Hal had become no stranger to seeing his son's huge loads, but this one was on yet another level. The sheer volume of cum that this one cumshot had produced was both impressive and intimidating. He was glad Carol was still on birth control, knowing that Gavin had pumped many similar-sized wads into her pussy in the last ten days.

It took Gavin a full minute to milk the last drops of cum onto his mom's butt. Finally spent, he flopped down on the bed beside her, gasping for air, a dazed look in his eyes. This was a good sign, thought Hal, as this is how he usually looked when the medication's nasty side-effect was finally giving out. In 10 or 15 minutes, Gavin would be back to normal with no memory of the incredible ass-fucking he'd just given his mother.

Carol was still on her hands and knees, looking like she'd bent over and had a water balloon full of donut glaze thrown at her asshole. She straightened up with some difficulty, stiff and sore from nearly five hours of intense sex.

"You ok?" asked Hal, admiring her big, wobbling tits and cum-covered ass as she got to her feet.

"Yeah, that wasn't too bad, actually," she said, using a bath towel to begin the process of wiping off Gavin's ejaculate, "I can handle that once in a while, if there's a need for urgency."

Hal was both excited and appalled to think that this wouldn't be the last time his son's big cock was in his wife's hot ass.

--

An hour later, Hal and Gavin were pulling out of Lorraine's driveway with her in the passenger seat and the trunk filled with boxes of her stuff. Movers would be handling the furniture and most of the trickier items, so Hal and Gavin would only be helping with the few smaller things that needed special handling.

"Thank you both so much for doing this," she said, looking over at Hal with a smile and turning to flash it at Gavin as well.

"Of course, Grandma, we're happy to. I can't wait to check out your new place!" said Gavin. With the side-effect gone, he was back to his usual, chipper self.

"It's nothing much, but with your Grandpa gone it's plenty enough for me," she said. Hal's dad had passed nearly five years ago, and though Lorraine had moved on with her life Hal knew this was a big step.

Gavin leaned forward from the backseat to wrap his arms around Lorraine, squeezing her in a hug through the seat. She patted his arm lovingly, and Hal noticed that, likely unintentionally, Gavin's forearms were positioned directly on Lorraine's chest. She had always been a rather bosomy woman, and Gavin's little arm squeeze pushed noticeably against her soft tits. A flicker of concern was erased when Gavin disengaged the hug. This was more of the innocent touchy-feely behavior that Gavin had been exhibiting since taking the medication. Outside of their sessions, Gavin was now frequently hugging and even cuddling Carol with no sexual intention. Apparently, this amorous behavior applied to his grandmother as well.

It was a short drive to Lorraine's new apartment complex, a nice, modern, ten-story building in the middle of town. She guided Hal to a rear parking lot from which they could access the freight elevator. Her unit was on the 9th floor, and it would be at least half-a-dozen trips up and down from the car.

The trio was in high spirits as they entered Lorraine's new digs with the first load of boxes. She showed them around a bit and they admired the view from her private balcony. Over the next 45 minutes, they went up and down between the apartment and the car several times, though the freight elevator was annoyingly slow.

Hal had stopped to use the bathroom following one trip up, and as he walked off the elevator on the ground floor he passed his mom and Gavin who were walking onto it with more stuff.

"See you up there," said Hal, thinking nothing of it as he went to the car.

By the time he had grabbed another box and was re-entering the building, his phone buzzed in his pocket. It was a text from his Mom:

"Hey, I guess the elevator stalled. Gav and I are stuck in here :("

With a grumble, Hal set his box down near the elevator and texted her back.

"Don't worry, I'll go tell the building staff."

The next ten minutes were spent by Hal liaising with the complex's front desk and security guard. They apologized for the incident and promptly called a repair company that would have someone over in a half hour or so. Hal relayed all of this to his mom, who replied that she understood and that they were fine and would just relax and wait.

Hal was led to the security office and on a small monitor the guard pulled up the feed from the freight elevator. Hal could see, with pretty good clarity, that his mom and Gavin were sitting on the floor chatting happily.

"You can stay here and keep an eye on them, if you like," said the husky female guard, "I gotta go out front and wait for the repair guy, they never know how to get into the building."

With nothing better to do, Hal settled into a little desk chair as the guard left him alone in the small, dark room. Over the next couple of minutes, he mostly just scrolled on his phone, every so often glancing at the monitor to see that Lorraine and his son were still doing ok. They seemed fine enough, but it was a hot day and Hal knew from riding in it that the elevator was very stuffy. He could see them both fanning themselves, their foreheads showing a light sheen of sweat.

It had been about five minutes when Hal noticed through the monitor that his mom was pulling off her thin sweater, revealing the t-shirt she had on beneath. It wasn't terribly sexy or anything (especially not to Hal) but the tee had a pretty deep V neckline that showed quite a lot more of Lorraine's chest than the sweater had. The removal of the sweater was nothing interesting to Hal, but he noticed on the monitor that Gavin seemed somehow... fascinated by the event. His head had locked into place the moment her cleavage had come into view, and he was staring at her chest with a strange, but familiar look in his eyes.

"Oh shit," said Hal, realizing what was about to happen.

He tried calling his mom, but her service in the elevator wasn't good enough. He was typing up a text to her, struggling with how to warn her, when it happened.

In the elevator, Gavin practically leapt to his feet. The rapid action surprised Lorraine, but not nearly as much as what came next. With a swift drop of his basketball shorts, Gavin's raging, nine and a half inch erection bobbled into view. The side-effect of his medication had returned.

Lorraine's eyes went wide, and she said something that Hal couldn't hear (the security camera didn't have audio). From the look on her face, it was "What are you doing??" or a similar phrase one might deploy when seeing their grandson pull out his giant pecker.

With a sinking feeling, Hal realized it was too late. His son was about to fuck his mom, and there was nothing he could do to stop it.

Gavin closed the short distance between him and the still-sitting Lorraine, his big dick bouncing and swinging in front of him. Lorraine was staring at it, too stunned to react when he pushed his hips out to let the meaty thing prod and rub against her face. She pulled away from it, but he just put a hand behind her head and did it again.

Apparently that was what passed as foreplay to Gavin in his animalistic state, and now he was ready for more. He bent down, grabbing the hem of his grandma's t-shirt and yanking it up over her head. She didn't stop him, didn't really even react. Just kept staring at the big cock that was still floating around her eye-level. He didn't bother to unhook her white, cotton bra, he just reached in and, one at a time, popped her soft, grapefruit-sized tits out of it.

Hal wanted to look away but couldn't. He'd never seen his mom's boobs before, and though they weren't perfect they were still damn nice. He did his best to disassociate, telling himself that he was just watching a young guy and a mature woman, and not his son and his mom. He had to see this.

Gavin squeezed and pinched Lorraine's big boobs, his hard cock still in her face rubbing against her nose and cheeks. Hal thought to himself that, if she'd wanted to, she definitely could have stopped Gavin by now. Pushed him away, gotten her tits covered up, and kept this situation from progressing. The fact that she hadn't suggested that at least some part of her was interested in doing it.

Taking his cock in one hand and some of her hair in the other, Gavin guided the big thing towards her mouth. Not terribly unlike when he'd fucked Carol's ass earlier, it took a few moments for Lorraine to adjust her mouth to accept something of such incredible girth. From the way it made her eyes bug out, Hal assumed that, like it was for him, Gavin's was the biggest dick she'd ever seen, and now she was sucking on it.

Hal checked the time. There was still at least 25 minutes left before the repair guy was supposed to get there and have the elevator running again. He couldn't decide what to hope for: that they would get there before Gavin and Lorraine finished, or after.

On the screen, Lorraine had rather quickly turned into a willing participant. Gavin no longer needed to hold her head in place and fuck her mouth; she was bobbing on it of her own accord. She reached one hand up to grab his shaft, stroking it as she swirled her tongue around the bulbous tip. Her other hand went to her left boob, mashing it and roughly pulling her own nipple. Jesus, thought Hal, embarrassed by what he was witnessing.

Gavin seemed to grow tired of the blowjob. He pulled his grandmother to her feet and started working on her pants. She helped him, her hands nervously fumbling with the buttons as Gavin took two big handfuls of her ass. Hal could see her smiling, her chin wet and shiny, and saying something to Gavin. Gavin, of course, didn't respond and just kept mauling her big ass. Hal could guess that she was questioning what the hell had brought all this on, as of course she knew nothing about Gavin's meds or their side-effects. And though she may have been questioning it, she certainly didn't seem interested in stopping it.

Lorraine's pants dropped to the floor, her cotton panties a moment behind. Her ass didn't have the perfect, round shape of Carol's, but was full and squishy and inviting. As Gavin pawed at it, she took his big cock in both hands, stroking it up and down, making his heavy balls bounce.

Moments later, Lorraine was bent over with both hands on the elevator wall as Gavin lined up to fuck her pussy from the back. Gavin was apparently done with pleasantries and as soon as the wide head of his cock found paydirt he jammed the whole thing into her with one hard thrust. Hal felt like he could hear her scream of joy reverberating throughout the building as Gavin plunged his cock in and out, sawing away at her juicy pussy.

Hal tried to look away from the monitor, telling himself he was a sick fuck for watching, but his eyes kept snapping back. He watched his mom's big tits flopping around as Gavin hammered away at her. His heart was racing, his dick getting hard. He was about to take his raging dick out of his pants when the door to the office suddenly swung open.

"Just got a call from the repair tech," said the security guard, poking her head into the room and making Hal jump in surprise, "they're five minutes out."

Hal thanked the guard but was more thankful that, from her angle, she hadn't seen the monitor and had again left the room. If she had looked at it, she'd have seen Lorraine's soft tits flopping around wildly as Gavin fucked her pussy hard and fast, his hips slamming into her pillowy ass. Hal could imagine the unmistakable sounds of skin slapping skin and hoped that no one on the floor the elevator was stalled on could hear them.

With a grimace, Hal watched his mother have an eye-rolling orgasm on Gavin's dick. Her body convulsed with the aftershocks of her orgasm, the waves of pleasure making her knees wobble.

Hal reached into his pants, his hand shaking as he wrapped it around his stiffening cock. He watched Gavin's sweaty balls slapping against his mother's pussy, her face contorted in pleasure. He knew it was fucked up, his son plowing his mom, but goddamn it was hot.

Gavin, heedless of her condition, continued to pound her, his strokes relentless. Without warning, he pulled out and spun her around to face him. Her face was flushed, her eyes wide, and her mouth parted slightly. Her expression was one of joyful wonder; at what had happened so far, and what might be coming next.

Gavin grabbed her by the hips and lifted her, her arms going around his neck as he hooked his elbows under her knees. It took them a moment to realign his cock, but once it was back inside her pussy it was a simple matter for Gavin to simply swing her body into his, slamming her down on his massive cock.

They fucked like that for what felt like a long time. Hal knew that the repair tech was probably in the building by now, and that any moment Gavin and Lorraine's tryst would be interrupted. Gavin, Hal knew, wouldn't care if he suddenly had an audience and would just keep fucking his grandmother until sated. That would surely be a problem. This needed to wrap up, and soon.

"C'mon, just cum in her," Hal mumbled, trying to will his son to finish quickly.

It took another two minutes of hard fucking but Hal's hope was realized. With a few hard slams, Gavin buried his big dick as deep into his grandma as he could, no doubt pumping a creamy load into her. Still holding her, he used her pussy to squeeze out every dollop of the creampie he was giving her.

A hot, sticky stream of cum erupted from Hal's cock, splattering onto the cheap, beige carpet beneath the desk. He squeezed his eyes shut, his body shuddering with the force of his orgasm. He kept stroking, each spasm sending another wave of semen onto the floor, a growing stain spreading across the fibers. When he finally went limp, he slumped back in the chair, his breath coming in ragged gasps.

Hal could see the shift in Gavin's expression. That orgasm, thankfully, seemed to have been enough to quell his hyper-virility. He let Lorraine get back on her feet, her looking worn out but satisfied. She dressed quickly as Gavin put on his shorts and sat down against the corner of the elevator, still catching his breath and not yet back to his normal self.

Realizing it was time to make a move, Hal stood up from the rolling chair. He glanced down at the dark cum-stain he'd left on the carpet, a mixture of shame and satisfaction swirling within him.

"Hopefully it'll dry before anyone notices," he thought, zipping up his pants and wiping his hand on his shirt. The image of his mother, impaled on his son's cock, lingered in his mind, forever etched into his memory.

Hal left the security office, arriving at the ground-level elevator bay where the guard and the repair tech were waiting for the now-fixed elevator car to descend. Hal hoped his mom and son were still dressed and decent when they arrived.

The elevator doors opened and a waft of humid air poured out. The smell of sex was unmistakable to Hal, but at least when Lorraine and Gavin emerged they were dressed and, other than looking very warm, showed no signs of how they'd passed the time.

"Is he ok?" asked the security guard, looking at Gavin's dazed expression.

"I think he's just a bit dehydrated," said Lorraine with a little giggle, "It got pretty hot in there."

Gavin was led to a bench to rest. While he slowly regained his true consciousness, Hal pulled his mother aside. Awkwardly, he explained Gavin's medication and its side-effect, leaving out the detail that he'd witnessed their entire sexual encounter. He even shared, begrudgingly, how Carol had taken on the responsibility of "helping" Gavin each day. Lorraine was surprisingly cool with, though the good fucking she'd just received probably did wonders for her mood.

"I'm just glad he's ok," said Lorraine, fanning herself with her hand, "If Carol ever needs a break, feel free to drop him off over here."

Hal groaned inwardly.