- It's aimed at or about teenagers (usually Played for Laughs) and the character is either a horny teenage boy, or another character, usually the parents, think that he's masturbating when he is very obviously (or sometimes not so obviously) not.
- The character masturbating is sexually frustrated, disturbed, perverted, or is a nerd/has no social life. When Sex Is Cool and Everybody Has Lots of Sex, masturbating is portrayed as a shameful last resort for losers who can't get laid.
- It's a military or a prison setting (or a single-sex boarding school). The masturbation here would be explained by the shortage of women (or men), boredom and loneliness.
- Artificial insemination due to lack of partners, incompatible sexual orientation, etc.
- In porn or erotica, it can be used for the sexual titillation of the viewers.
List of masturbation tropes:
- Breaking In Old Habits - A character receives a replacement hand and immediately uses it to masturbate.
- Caught with Your Pants Down - A character is caught masturbating.
- I'll Be in My Bunk - A character who steps off-stage is humorously portrayed as leaving to masturbate.
- Jizzed in My Pants - Yeah, self explanatory.
- Mistaken for Masturbating - Characters think someone who isn't masturbating is.
- Porn Stash - A character has a personal collection of pornography, and can usually be assumed to use it as an aid to masturbation.
- Poor Man's Porn - A character gets off to something not strictly intended to be used for that purpose.
- Self-Abuse - Masturbation is portrayed as bad for you.
(Opening door) Oops! Sorry! When you said you were going on the computer for a while, I just assumed you'd be on TV Tropes!