The goatse.cx lawyer has informed us that we need a warning! So... if you are under the age of 18 or find this photograph offensive, please don't look at it. Thank you!
as a noun it would be the below, not a noun would be the example above; refering to homosexuality of the gaping anus man or just dubbing the man as "goatsecx"
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?"