When your jerkin it in private and someone like that dumbass karkoon comes in and makes you have to stop and hide it. Soon after your woody is still there and it begins to hurt and throb.
Man i was watchin' this awesome pornographic film last nighht when my mom came in. I got such a throbbasaurus.
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.