When you and your girlfriend are doing the dirty on your friend’s basement couch and you proceed to throw both your legs up on the back of the couch and then swan dive into your girlfriends anus or preferred orifice.
“Hey Jamie? Did you give your girlfriend the ‘ol Texas Slamhammer on my couch last night?”
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?"