Hi, If you have a problem of leaking sperm, then go to pegym and look up kegels, its an exercise that will strengthen your PC muscle, this one muscle does all kinds of things, its the muscle we use to stop urine, and pumps extra blood into our p***s, its also pumps our sperm out for ejeculating, so it can be a very busy muscle at the weekends.
Good Luck
Im not a doctor but have some experience. Mostly its caused from over masturbating. The parasympathetic nerve that is responsible for shuting the valve where the sperm is held has been overworked.