After sex why is it that i always have t pee often?

"honeymoon cystitis": This is what some people have called the tendency for some women to get bladder infections after intercourse. This is what it sounds like might be affecting you. Try urinating before and immediately after intercourse, to empty the bladder of any bacteria that might be introduced into the urethra from physical manipulation in the area. Some even need to take an antibiotic pill every time.