<s>[INST] i am 28 yrs old, after masturbation or sex next day  i feel pain near my ass hole and in legs, i have to take some pain killer, pain is so much that i can't resist it, i am going to marry and i m very worried please tell me what may be the reason for this. is there any problem? [/INST] Hello, Some people like you tighten their whole body muscles during masturbation and at the time of ejaculation causing pain in body/ legs or back.  Learn to do in a relaxed manner. Hope I have answered your query. Let me know if I can assist you further. Take care Regards, Dr K. V. Anand, Psychologist </s>