How long must I masturbate I'm 13
Your question is very strange. When you start masturbating the penis will slowly become erect and big. After stroking for a few minutes you will experience a pleasurable sensation and the semen from the penis will be released at jet speed. At that time you will get a pleasurable sensation. This can be done by solo. If you have a close and trusted friend you may do mutual masturbation.
Generally some other person especially the opposite sex touches and fondle the Penis it will be more interesting and pleasing act.