When you masturbate with or with your friends while talking about sexual scenes. When a guy frienderbates he masturbates with his friends while talking about girls he had sex with or girls he wants to have sex with. When a person calls a guy a "Frienderbater" the guy will find it offensive and kick you in the penis. If you tell that to a girl a girl will kick you in the vagina.
Tim: Hey Lucia what did you do yesterday? You didnt respond my text until 26 minutes. Lucia: oh. I was frienderbating with Ann and Nikki Tim: oh. o.o .. well i frienderbate too *lies*