The act of engaging, after a solid regimen of vaginal sex, in the act of anal sex; also known as sodomy. One can also hop onto the back nine right away if possible. This phrase is a simile derived from the game of golf when one plays the last nine holes on an 18 hole golf course.
Me and my girlfriend were having great sex last night when all of a sudden we tried to switch it up and ended up "playing the back nine" wink* wink*.
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.
FRIEND A: "Did you just take a stealthie of me?"
FRIEND B (turning phone around): "no I was just using snapchat's new filter, see?"