It was Friday, and Peter was resting inside the underwear listening to soothing drone Dan's voice. Dan was really doing a great job on his part of the presentation that his geeky partner had done much of the actual research for, or at least it sounded like Dan was doing a great job. Peter couldn't understand most of it through the clothes, but it was relaxing to hear the calm, confident rhythm and cadence. Peter took a small amount of pride in knowing he'd done his part to help Dan get ready for this key moment: Dan wouldn't have to worry about needing to pee during his presentation, because Peter had made sure he visited the restroom just before class. Of course, Peter hadn't had very much control over that situation, but nevertheless he still thought of Dan as a family member and wanted him to do well.
Peter was finally starting to settle into his new routine as a very special part of Dan's body. He knew approximately what he could expect to be used for and when. He knew that he would be called on several times a night to have an erection while Dan slept. He would have to let out some of Dan's semen about halfway through the night because Dan was prone to wet dreams. He knew that he'd be up before Dan in the morning because part of being a penis is giving a man his morning wood. He knew that Dan would wait until Peter was halfway flaccid again to have his first piss of the day, which would be the longest piss until after football practice. He was especially learning to look forward to his special time with Dan's big strong hand before the evening shower, because that was when he could really make Dan's day just by letting Dan make his. As a human, he would have been disgusted by the thought of watching his brother jack off or letting his brother jack him off, but masturbation had become into his most treasured quality time with Dan since he turned into a penis. Those were the times when Peter really didn't regret turning into a penis.
Peter had admittedly made some discoveries about Dan that he wasn't thrilled with. Being someones private part means knowing their deep dark secrets, after all. For example, Peter finally knew for sure that Dan pees in the shower. Not just once in a while, either, but every time. Peter was always kind of disgusted with people who do that, but he had to go along with it. Whenever Dan wanted to go pee, it was part of Peter's purpose in life to let him, so if that meant spewing out a load of urine right where Dan's roommates would later be standing to clean themselves off, Peter was going to open up his little urethra mouth and let it all out then and there.
Most of the day was reasonably boring after Dan's presentation, but tonight was going to be a little different than Peter's private evenings with Dan so far. Tonight it was party night. Dan walked in, and Peter felt the rhythm of the electronic music pounding through his cock body along with Dan's happy heartbeat. He heard his owner's loud friendly voice greeting male and female friends from all over campus. People were shouting or just talking quietly. Dan spent some time dancing, and Peter felt like he was dancing too as he flopped around inside Dan's pants. Dan must be drinking, because Peter was starting to feel tipsy. Through it all, though, Peter managed to raise himself up into an erection. Dan was talking with some girl with a very attractive voice. A door closed, and things were much quieter except for their two voices. The pants came off and Peter stiffened himself up a little more at the sight of the naked lady with the waiting vagina before him.