Your surprise and pain turns to rage. You glare at your attacker in the mirror. Your gut feels suddenly empty. You clench your butt cheeks tight, and begin to pull him deeper inside you.
At first he laughs, "Now you're getting into the spirit of things, boy. Milk my cock!"
But soon he's pounding on your back, "Stop! Stop! You're ripping my dick off!"
You just pull harder trying to fill the empty inside you. He screams as his hips are pulled inside you, and his body bends like a clothes pin. There is a loud snapping sound of bones breaking. Your attacker's back slams against his own calves, as he sinks up to his navel and thighs inside your buttocks.
"This can't be happening? It can't! Please stop!"
"You shouldn't oughta start things you don't plan on finishing," is your reply as you moan, and draw him in up to his pecs and knees.
He's now begging and pleading as only his head and feet are sticking out of your ass. You stand and turn sideways so he can see himself. It looks comically horrific, but he sees only the horror. Him reduced to a head and a pair of feet, and your gut swollen with the rest of him.
"Please I've got a thousand dollars stashed. It's yours if you let me go," he bargains.
"Dude, what are you going to do with only a head and feet? I've already started to metabolize the rest of you," you answer matter of factly. You pat your swollen belly, and he grimaces.
You shift your bowels and release an enormous stinky fart. The gas rushes over his trapped body. The pressure and movement is terribly stimulating, and despite his predicament, the bike stud moans in ecstasy.
"Now you're getting into the spirit of things!" you say with a laugh, and pull him in up to his nose. You hold him there as he tries to speak, and you moan. "Oh, yeah, I love rim jobs from the inside."
His eyes go wide. Enough playing, you inhale deeply and suck every last bit of him inside you.
You look at your swollen gut in the mirror and shake your head. You inhale hard sucking in your gut. Amazingly it does suck in. Your chest expands, your shoulders widen, your insides churn as this sudden new mass is reallocated within your body to turn you into a giant muscle stud.
You shit out a leather vest, boots, socks, underwear, and jeans. The hat was already on the floor from when the biker bent backwards. Your own shirt is in tatters, and your jeans are splitting at the seams. You pull your cock out. It's now twice as long as it was, and the cock head looks like a face. The piss slit is moving like a mouth. You hold it up to the mirror. The biker can see his fate now. His facial features are fading as he becomes your new improved cock head.
"Well, I did come in here to take a piss..." you say strolling over to the urinal and letting go a hot torrent of yellow piss. You can almost hear the little guy screaming.