<s>[INST] sir i have just turned 21 and im unmarried sometime a desire comes into my mind from nowhere and i make my way to bathroom and start playing with my penis meanwhile a white substance appears to come out of my penis. in early days i didnt feel any pain but with passage of time i hurts me. is it a serious matter? if yes then plz help me to get ride of this  problem// [/INST] Hi, I had gone through your question and understand your concerns. Well, this white substance is probably semen which is normally ejaculated during masturbation. In rare cases as a part of STDs it may be pus, but then it would be discharged spontaneously. Certain degree of pain is expected and depends on intensity of masturbation, but if there is significant pain then it may present reinfection or prostatitis and in this case you should do urinalysis and prostate ultrasound. In every case, I don't think this is a serious problem. Hope this answers your question. If you have additional questions or follow-up questions then please do not hesitate in writing to us. I will be happy to answer your questions. Wishing you good health. </s>