Definitions by smartJAVE1

Bym 

It means to go masturbate but your the one saying it or what you could say "Beat Your Meat".

Brother:time to enjoy myself
Sister:EW!
Brother:what!?
Sister:go bym in your room!
Brother:I am
Sister:oh,still EW!

Bym by smartJAVE1 November 19, 2018