facebook popper
A Facebook popper is someone who checks who's online just to see if they're worth talking to and then logs off like they just got a slap from a giant chicken.
He logged on, saw his ex was online, and popped off like he just got fired.
She checked who was online, saw no one cool, and logged off like she was escaping a prison.
He logged on, saw no friends online, and popped off like he just lost a million dollars.