unpenis is a verb. when you unpenis someone it means to cut off their penis. haha bye bye penis. this could be while they're going beddy byes or when they're wide awake.
me; haha unpenis *cuts off penis*
sam: oh no my penis *bleeds to death because bye bye penis*
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.