She taunts him, but he's too addled to care

This was the first time that Tom had bottomed, had been fucked in the ass with someone else's cock. It would not be the last. Even if they did turn Sarah 'back to normal', a series of words that felt more and more inaccurate the more he considered them, there was no chance he could go without feeling this again.

His love for her cock, his love for being a good submissive bottom, was the only thought that stayed lodged in his head as Sarah's thick green cock started to penetrate his asshole. Sensation overrode reason. In the aftermath, if asked, Tom would only be able to describe it as a spiritual experience. There was pain in there, somewhere. Pleasure. But it was more than that.

"You're such a good fucking cocksleeve, for a human," Sarah told him, growling the words as she thrust her hips. "You should worship me for what I'm doing to you. No, fuck that, you should be worshiping me anyway. You call yourself a man, but this is your proper place. A bottom bitch, bent by the weight, the strength, the cock of someone you know is superior to you."

Tom was being used, like a sex toy. He couldn't moan, his mouth had been taken away, so all he could do instead was breathe in and out through his nose, the pace of it ragged and frantic. He couldn't cum, for he had no genitals with which to cum. All he could do was experience the bliss his wife...no, not his wife, his owner offered to him, and let his mind be filled by her words. That was what a good bottom bitch did. Shut up, take the cock they were offered, and revel in the joy of obedience.

The bed threatened to break as, after what felt like an eternity of getting it inside, Sarah finally bottomed out in him, the head of her cock probably lodged somewhere in his intestines. Then, she pulled back, and started moving back and forth. Doing so wasn't as mind-shattering as the initial insertion, but his ability to think was destroyed once more anyway, once it became clear the thickest part of her cock was being rubbed back and forth directly on his prostate.

The entire time, her words didn't stop. "Even with my touch, your asshole is still so fucking tight on my cock. I didn't realize how right I was before. Without the lubrication and capacity I gave you, I really would have killed you with this cock. Of course...you'd fucking love to be killed that way, wouldn't you? Fuck, just watching you spasm in pitiful uselessness, nothing but something for me to use, is getting me close. I don't even think I'll be done after one load, though. I'm starting to think, why should you be my only toy? I'm sure I can find a woman happy to take my cock into her pussy, with a few adjustments. And if I can't, I can use my musk to make her want it. Then, you can watch, silent and horny, as I fuck her on our bed."

Hearing her talk of this, seemingly just letting her stream of consciousness out to tease him as much as possible, made Tom start to squirm even more. A small part of him was terrified at the idea. This was fun, but he didn't want to actually lose his wife!

But...it was also arousing. Oh so arousing. To truly be nothing, a piece of furniture to her cheating on him. No consideration given towards his experience, except that which would make him squirm the most.

"Just...talking about it...fuck!" Thrusting all the way inside, Sarah's thick cock suddenly pulsed and jerked inside of Tom, and he felt her cum start to spurt out, filling him, claiming him. There was so much, when she finally pulled her thick green cock out of him, a stream of cum followed, and even after all of it had spilled onto the bedding, Tom could feel almost as much left behind, still in his system.

Looking hazy and revelerous in her afterglow, her first ever afterglow from cumming with a cock, Sarah gave him a shaky smile, the edge of ruthlessness gone from it. "So...what do we do now?" That would be the question, once he got his mouth back. Should they finish this change out, turn her back? Should they indulge in it more, perhaps never actually stopping? Should they...take up the idea she'd suggested, of introducing cuckolding into this?