<s>[INST] I was masturbating a few moments ago and when I rolled over I managed to jab the center of my penis on the pin on my belt buckle (that goes into the holes). Though it didn t pierce the skin (blunt trauma) it certainly hurt like hell, blood started coming out of my penis. The bleeding and pain has stopped, but I m really freaked out. What exactly happened down there? [/INST] Thanks for asking in Chat Doctor forum In Short: You might have injured your frenulum(fold of skin which holds foreskin when retracted. Explanation: Frenulum tear might have caused this as you injured yourself with belts part. If bleeding, pain has stopped, no wound and if you are able to retract foreskin normally during sex then no need to do anything.  If not visit a doctor for further treatment. </s>