I wanted to know what kind of problems can a male cause himself to have if he doesn't allow himself to release sperm after having sex.
It would depend on how he prevented his ejaculation. Most men would have difficulty preventing ejaculating semen because sex brings on orgasm when the body tenses up in pleasure. At the same time ejaculation takes place.
If a man got to the point of ejaculating and managed to squeeze his penis to stop his semen from coming out, the pressure would force the semen backwards and up into his bladder. This would injure the sphincter muscles at the base of the bladder that keeps him from peeing at the wrong time. It can also increase the odds of him getting a bladder infection.