You have a dream that you're in your Bio Class, and the professor is going on about how environment shapes evolution. You wake up and look at Richard curled up in a furry ball in his cage. His environment is a cage with less than 100 cubic inches of space. You take out the watch, and turn the hands forward a bit. Richard becomes a tiny toy dog, then a tiny monkey, and when you set the hands back where they were when you devolved him, he becomes a tiny apish creature. He looks vaguely human, you wonder if he can speak. You rattle the cage.
"Eep!" shouts Richard jumping up. He's a lot hairier than he had been, but then he's in an environment without clothing, isn't he? You note. His prick seems a lot bigger too. You wonder where you might find him a mate. The lemur-man knuckles it over to the edge of the cage and looks at your digital clock. "It's only 3 AM! What do you want!" he squeaks. He strolls over to the pellet tray. There's a partial one left. He gnaws on it. "Don't suppose you got any more Oreos? This stuff tastes awful!"
You pause dumbfounded for a moment.
"No more Oreos, Richard, but I do have a Klondike Bar. What would you do for a Klondike Bar, Richard?"
Richard looks greedily at your minifridge, and then at you. You notice he's sporting a boner. If his rep is true, you interrupted his daily routine. After practice he reportedly had sex with his girlfriend, purportedly cumming five times. He did this every day. But today, it was way after practice, and he hadn't laid his girlfriend once.
"Lemme out of this cage, take me over to your bed, lie down and let me show you," Richard said smugly.
You open the cage, and carry him over to your bed. You lie back, and set him on the bed next to you. He scrambles up your side and onto your belly.
"Hey, that tickles!" you giggle and abs shake violently.
He looks back at you and smiles, "Going to do more than tickle you!"
He runs toward your crotch, and makes a flying tackle through your fly and begins wrestling with your rapidly growing penis.
"Whoa!" you moan. He's jerking you off. The next thing you know, your fully erect penis is sticking up out of your fly, and rat-man has lined his own boner up with your piss slit and is fucking you silly. You've heard about sounds, but never tried one before. Waves of pain and ecstasy flow through you. Suddenly, your cock explodes. A heavy stream of cum blasts furry Richard back on your belly and covers him with a puddle of white goo.
He's laughing and looks back at you and squeaks, "So, does this earn me a Klondike Bar?"
You nod. You scoop him up and take him over to the mini-fridge, and open it up and pull out a Klondike Bar. You carry both him and it back to his cage. You set him inside. Unwrap the chocolate covered ice cream bar and put it in the cage. He pounces on it. You close the cage, and go back to bed.