When I was younger, I used to like to masturbate with a full bladder-it made the plateau phase and especially the orgasm much more intense-I loved it! But now, it seems like having a full bladder just kind of distracts me, and I'll pee if I need to before I start my masturbation session-then I don't have to be interrupted later...
I like to empty my bladder before even getting started. I find that if I'm holding back having to pee, it's decreases the intensity of my orgasm.
If i wake up in the morning with an errection and decide I need to masturbate, it definitely enhances my session not to pee. Any other time of day i pee first.
If it does not distract you from the task at hand, it is better to pee after you ejaculate (guys). It cleans out the urethra and avoids the messy dribble of semen out the pee-hole, since some of the cum still remains in the urethra after ejaculation. Many women pee before having intercourse, where the pressure of the male body on the full bladder can make sex uncomfortable.
even if i pee before, somehow 5 mins later i need to pee again so bad even if it's just a little. if i do it in the morning i can't be bothered to get up first but then it's huge rush not to piss myself...