Why do i feel pain at my perineum area after ejaculation ? am 20 years old male, it is like a muscle is over tense or something... seems like a cramp

Muscle contraction: When you ejaculate you bulbocavernosum muscles contract. These can sometimes cramp and cause that pain. It is not dangerous unless you are having other symptoms.

Well: Some can get a perineal cramp, give urself a break, could be prostate, especially if u get pain when u pee or fever.

See your doctor: Problems like these can only be correctly handled by your doctor in person. He/she needs to listen to you, perform an examination and possibly run labs or other tests. That's the only way he/she can find out what's going on and what to do about it.