It means you be lying. So like if you say something like I killed somebody yesterday and said later that you was fucking a hoe, someone you told that bullshit to, will say you be cappin
You: my side bitches Bianca and shonda'laquesha was getting fucked yesterday and this other side hoe showed up and I shot her.
Jon Jon: nigga you be cappin now stop lying before I take yo side bitches and yo momz
Jon Jon: nigga you be cappin now stop lying before I take yo side bitches and yo momz
by Stopcappinnigga September 29, 2018
Dang you cappin
by S cycling daddy December 27, 2019