You have to pee after you have sex or you'll get one. Also, taking cranberry tables (you can get those at Walmart or a pharmacy) can help prevent them. I used to get them a lot!

I take cranberry pills after sex! And drink water. Also peeing before AND after is important.

Yeah it helps to pee a few minutes before to empty your bladder then to use the bathroom again after. Also water and cranberry helps. Especially if you're doing it unprotected.