A.T.B. stands for Anal Tongue Bath. Its the art of licking your partners arsehole for sexual stimulation or to clean their brown balloon knot. It is not the most plesant activity and can lead to bad breath depending on the diet of the partner
Man. "Oi honey, im up for a good ride tonight"
Woman. "No problem, you can get me going by giving me an A.T.B."
Man. "Fuck you, we had an indian take away last night, your ring will be nasty"
When a man or woman grabs another woman from behind on the ass, trying to force his middle finger in her clank(vagina) and his thumb up her shitter (ass). This mirrors how to hold a bowling ball (Bruinswick being the most famous make)
Damn, that mutha fucka hit me so hard on the Booty last night I think he Bruinswicked me.