Is it common for a 15 year old son to be masturbating . He was taking a shower this morning , took a long shower . I called his name but he never answered . I walked in and he pulled the Curtian away and I saw he had an erection . I over reacted and yelled at him that about him not hearing me and I'm sure he was embarrassed . What should I do , I feel awful but here I am also confused on what to explain or how