Natural Selection

Linh looked her dead in the eyes, smiled, and continued to finger herself and moan, watching Cathy's eyes widen in horror as she realized the trick Linh had played on her. It was too late though, Vince's cock was already inside of her and his hand had a firm grip on her breast, she could not wiggle away.

Vince was slowly pumping himself further and further into her, as his hand crept down from her breast to her clit. As she felt herself building towards an orgasm from a strange man, both the horror and ecstasy of the situation washed over her, Cathy was powerless to stop what she had set in motion, she did not think she would stop it even if she could. She began to bite her lip as Vince pushed further into her than any man had.

He was pushing in too far, she was squirming with pleasure. If he didn't stop, she was not sure she would be able to control herself, she did not want to make a scene and wake her loyal husband. She reached around to stop Vince, her hand gripping the shaft of his cock, she was shocked there was still so much shaft left for her to have to accommodate.

Now Cathy could help herself no longer, she began to writhe in the dark delight of it all. Her tight, loyal pussy was being stretched beyond its limits buy a long, thick, stranger's cock, all while another woman watched, and while her husband slept peacefully on the other side of that woman.

She let out an audible loud gasp as Vince's cock pushed through whatever resistance her pussy had left. Linh immediately shoved two fingers into Cathy's mouth to silence her and not ruin the fun. Cathy started sucking the pussy juice off of Linh's fingers, and she was grateful her mouth was busy doing something other than making sounds that might alert Clark to what was going on only a couple feet away from him.

At this point Vince was so deep inside of Cathy that it felt like he was fucking more than just her pussy, it was as if he was fucking her entire existence. She felt he was either going to break her entire body with his cock or he was going to make her orgasm so hard she would die, she did not know which she should prefer.

Finally Vince had entered her up to the hilt, she gasped a sigh of pleasured relief. But, her relief was short lived. Although he had slowly entered her, giving her pussy time to accommodate his size, he was now increasing the tempo of his thrusts.

Her pussy was molten hot after all of the teasing the night prior, she had never felt this horny, this wet, this satisfied. The immense physical pleasure, combined with the taboo of getting stretched by a cock much larger than her husband', sent her over the edge. As soon as Cathy's orgasm began, she knew it was going to more intense than any she had ever had. In seconds, she was cumming so hard her body was shuddering, her pussy was writhing, she was rapidly clenching down then releasing the thick cock, she was gushing all over it, but Vince did not stop pumping in and out of her.

He could feel her muster all of her energy into gripping his cock tightly with her pussy, intensifying her orgasm, he smiled as he felt her orgasm ripple up and down his shaft. Now she was in a puddle of her own fluids, but he would not relent. He mercilessly continued pounding in and out, never letting her come down from her orgasm, rubbing her clit in irregular patterns to keep her attention focused solely on pleasure.

Linh now had shoved her tongue inside of Cathy's mouth as she continued to writhe, drowning out any noises that might give her betrayal away to her husband.

Cathy was in ecstasy, she was cumming so hard she had let go of her guilt, embarrassment and shame, she had never felt more alive in her life, she was living in the moment for the first time in a long time. She felt her brain turning off, Vince was fucking her so well it felt silly to think about anything other than the pleasure washing through her.

It was not until Vince pulled out of her that she was able to think clearly again. She was finally coming down from her orgasm and thanked the heavens Vince stopped himself before cumming in her. She graciously waited for him to shoot his load onto her ass... but she was not so lucky.

To her horror, Vince rolled her from her side to her belly, got behind her, lifted her hips up and re-entered her doggy style. Now that Linh's tongue was no longer in her, Cathy let out a whimper as Vince stretched her out from this new angle. This seemed to rouse Clark slightly, luckily the moon was behind the clouds again, Cathy prayed the moonlight would not re-emerge and expose her betrayal.

Vince's large balls were now starting to violently slap against Cathy as he used her. She reached one of her hands between her legs to hold his balls still as he fucked her. Her hand massaging his balls finally set off Vince's orgasm.

He thrusted his cock all the way into her and held it still as he began to shoot his cum deep inside of her. Her body was greedily accepting Vince's cum deep into her womb, in places her husband could never reach. Cathy bit down on her thumb as tears ran down her cheeks. Some of her tears were from the overwhelming pleasure she felt, others were for the guilt of cheating on her husband, some were tears of anxiety over the fact this man had just cum deep inside of her unprotected, married pussy.

After Vince finished filling her, he pressed his body weight down onto her, his cock remained nestled deep inside of her as he rolled her to face Linh and her husband. Now his cock was serving as a sort of plug, keeping his spunk lodged deep inside of her, not letting any of it escape until she was fertilized. He was doing his best to knock her up, and there was not a damned thing she could do about it. She just lay there, staring into the darkness that separated her from her husband.

As the moon again emerged from behind the clouds, she was able to make out Linh licking her hands, sticky cum splattered all over them. Linh must have jerked off Clark to the sounds of Vince fucking his own wife, Clark was almost certainly still clueless Linh and Cathy had somehow switched spots in the middle of the night.

It was only after Vince began to snore and his grip softened from her hip, that Cathy was able to wiggle off of his cock. She could feel some fluids slowly trickle out of her stretched and swollen cunt. She had never felt her pussy lips so swollen, almost engorged, still lightly pulsating. She gently rolled Linh towards herself and leaped over her, switching one another back to their rightful places. She gently lifted Clark's arm up and draped it over herself, then nodded off to sleep, thoroughly exhausted, blissfully used, and completely filled up.