Slapping bag refers to the act of sexual intercourse with an attractive female counterpart. The term comes from the act of ones ballsack (the bag) slapping against the female partners ass during rough sex.
Bro1: Yo did you slap some some bag last night?
Bro2: Yeah dude I was slapping bag with that hottie all night.
Bro1: Niceeeee.
Bro2: Yeah dude I was slapping bag with that hottie all night.
Bro1: Niceeeee.
by Gazman1 January 25, 2017