Peter was a person who didn't understand boundaries. Peter thought he and Paul were friends but Paul didn't like how Peter would take advantage of Paul.
And this time was no exception. Paul hadn't locked the door because he was home and didn't expect Peter to come by. So Peter just barged in without knocking and went first to the fridge to make himself a sandwich, not bothering to ask Paul first if he could. Peter made himself at home assuming that Paul was out.
Then Peter discovered Paul's cock and balls. "Paul, you got yourself dicked. It's been happening all over: people turning into their own dicks. I bet you're just aching for some attention."
Peter dropped his pants and stuck Paul on so that Paul was now Peter's dick. Then Peter began casually stroking Paul while continuing to wander Paul's home. Paul was just getting further edged without release.
Peter needed to pee because of that big cup of cola he drank. He didn't think about Paul's feelings at all and just started peeing in the toilet. Paul about gagged on the taste of urine.
Paul thought, "I'm going to get you for this. How dare you come in my place and just use me like that!"
Peter wasn't done though. Peter got on Paul's computer and found the site where Paul performed for an internet audience. "So you like an audience. Well let's give you an audience." Peter activated the site and Paul's camera. "My name is Peter and this is Paul. He got himself dicked. How much would you pay to see me use Paul as my own dick?"
The money started rolling in with many requests like, "yank his balls" and "slap him against your leg".
"Hey Paul, you're popular. I...we could make lots of money. I should get you tattooed with my name. Oh, someone is suggesting I give you a Prince Albert piercing. What do you think about that?"
Paul wondered what would happen to the tattoo when he changed back into human. Would he be stuck with a tattoo of Peter's name on his dick? Paul didn't like that at all.