You don’t have to pee after sexual intercourse although it isn’t harmful to do so, and it might even be helpful. Many people believe that peeing soon after sex, lessens the chance of getting a urinary tract infection; however this has not been confirmed by research studies. We do know that peeing itself causes a series of contractions that helps move the urine along until the bladder is empty.
Read more about UTI’s and how to lessen your risk of getting one: https://youngwomenshealth.org/2013/01/02/uti/