>>397626
>I pee a lot, like every 15-20 minutes on average
This sounds like something you really should see a doctor about.
>>397650
It's difficult to pee with an erection, and REALLY difficult to lose your erection once you put it in someone's butt. And once soft, it'll slip out easily as there's nothing to keep it inside, especially when you start increasing the pressure by filling it with liquid.
That said, I can pee with an erection. It's just unreliable, and I've never tried it during sex.