butt cheek kisses is showing your woman how special she is and how much you love her AND you will do anything to prove your love and total devotion to her.
To slide a "rod" between two spink cheeks and pumping it back and forth until climax is reached. (without actually penetrating the colossus cages of brown town)
Unlike a fart, when air gets trapped in one's butt cheeks, usually while sitting, and a small pocket of air pops out. This is similar to a vaginal queef.