When you suck a fart out of a someone's ass, hold your breath and then kiss them, releasing the fart gas into their mouth.

when you're hungover as shit after a spending a night drunk as a skunk

spreding you ass cheeks then puing you ass hole on some one. Leaveing a mark on some one like when some one kisses you with lip stick on. But intead of lip stick its shit stick.

to fart and then dedicate it to somebody.

Brown Kiss is the act of kissing someone on the lips with your asshole while they sleep.

If your are giving your partner a very lucious rim job, leading to a fece eruption and then go to another partner and give them a kiss on the lips. A brown kiss.