What is Beating A Fatty?
1.
Masturbating : When you get a hard on, after seeing a pretty woman, or for just no reason at all and then you beat off because your dick is hard and you are almost there.
"Jeff's not going out tonight, he's beating a fatty at home."
nick's got a date with his computer tonight.....he got a boner from this girl at walmart and now he has to finish off..and beat a fatty
See