I arched my back and raised my ass as Runt got onto the bed behind me. His tongue bath must have helped stretch out my asshole quite a bit, because he was able to jam 3 fingers in with almost no resistance. I moaned at the entrance, ready for more.
As Runt leaned forward, I felt his hairy chest rub against my back. "Oh, are you ready?" Runt asked sarcastically in my ear. He removed his fingers and I could only whine in response. He laughed to himself, but leaned back to line up his rock-hard dick with my hole.
As he pushed into me, the initial pain of this largest intrusion brought me ever-so-briefly to my senses. Three hours ago a smooth-skinned imp with a bad cockney accent invaded my home, and now a hairy demon with a half-stolen cock was about to fuck me senseless. The transformation, the speed at which everything was changing, was purely intoxicating.
My thoughts were cut short, though, as Runt's dick stretched me out. My hand shot down underneath myself to my shrunken knob and began to stroke furiously. As before, I felt no fear that Runt would let me come early. He continued to push slowly into my self-lubing ass, squelching deeper as I continued to produce juices in my frenzied state.
Runt himself started to moan as he got halfway(?) into me; his cock seemed to widen endlessly, pushing further. I heard myself moaning deeply, and my other hand went to my chest. My nipples were on fire like never before in my life, no doubt yet more of Runt's sexualizing influence on my body. I gave one a little pinch and lost my breath, which was inopportune as Runt took this moment to shove another inch in. He must be mostly there!
Runt leaned down again to my ear. "You're less talkative than when I was eating you out," he said on an exhale. I gasped in lieu of a response. I caught the grin out of the corner of my eye just in time to take a deep breath, because once he leaned back he shoved the rest of his cock into me. Somehow, impossibly, it felt like another five inches. Despite the instinct to clench, the move wasn't painful -- Runt must still be manipulating my ass to make this hurt less. I heard and felt a soft thwump as Runt's balls swung forward and hit my own engorged ones, pushed back by my furious jerking.
"Oh my God," I let out.
Runt laughed. "I guess you could say that, yeah." I couldn't contain the small laugh that escaped me.
"Well, you know what's next, right?"
Wanting to surprise Runt for once, I had an idea. "Yeah, let me show you."
I pushed myself back and up into him, and then turned and used my weight to lay back on him. He got the message and went back on the bed swiftly, holding my waist so he stayed firmly inside. Still facing away from him, I pulled up just a bit, and slammed back down onto Runt, fucking myself onto his enormous cock. Runt grunted appreciatively, and I continued to ride him.
On each rise I managed to lift an inch or two higher, making the ride back down that much more intense. On one, I turned 180 back to facing Runt, and came down, landing my hands on his (now more muscular?) hairy chest. Where I would have been disgusted before, I reveled in the sensation of running my hands along his pecs. I rose up and grabbed his nipples as I came down, drawing out the first surprised sound he had made that night.
Runt grabbed my thighs and held me down. "I have to explain something first, Derek." (It hit me just then that I had never told him my name.)
"My power comes from human reaction to these changes. You've been... perfect. Better than I could have imagined at feeding off of this. You're more passionate that you know. I've lied to you -- no one is chasing me. That's my in."
It wasn't exactly earth-shattering to know that he lied. What was surprising was the honest admission. I noticed that I wasn't in a horny fog, but I wasn't feeling disgust or regret either. Mid-sex, and everything there felt... paused. This conversation had to happen.
"I can do a few transformations without desire. The pig snout, stealing your dick... it would have all reverted in 24 hours anyway. When you approve a change is when it sticks. Your balls growing, or your ass, for example. I was planning on giving your dick back with an extra inch, you approving it, and then me having you. After the third approved change, you'd be mine. I would be able to change you endlessly and feed off of your reactions, horror or pleasure. But you're special, Derek.
"Here's the deal. I want you to trust me. So I'll give you two options -- we stop fucking right now, I put you back to how you were before and we ignore this. Shit, I'll even give you the bigger balls as a present. You can be who you were before and I'll leave. But think about this: option two is we finish this. I fuck you until we come, but instead of me taking you, we partner up. I can't give you any powers, but I can promise that we won't do anything you don't want to. My only ask is that we use you to broaden this experience, we get more people to react for me. Limitless possibility, and it won't even cost you your soul."
I was shocked. Somehow I had escaped what could have become eternal torment. But feeling how I have with Runt... it's been the most powerful and positive thing I've felt in years. He was intoxicating. Could I give up who I was, for this?