To try to have sex with a woman while she is sleeping. Usually this is done to a girlfriend or wife. Otherwise some of the more conservative people could profile this act as rape.
Guy 1: Hey man what are you doing?
Guy 2: Nothing just at my house and my girl is asleep and I really need to bust a nut.
Guy 1: I recommend you sneak one in.
Guy 2: Capital idea!
A type of fart that is done while sitting, the one-cheek sneak is done by leaning to the side to let the gas excape. Very handy when sitting on a smooth, hard surface while wearing shorts, to prevent "hovercraft" sounds.
To avoid disrupting the classroom, Johnny let out a one-cheek sneak, and nobody was the wiser.
the act of quietly squeezing out a fart when sitting down by leaning to the sideslightly and raising one cheek.
My girlfriend always knows when I fart because even though I do the one cheek sneak, I always give it away with my farting facial expression. Not to mention that the room also smells like a fucking animal died in there!