That lowkey steal your girl...but not really ass dude. Cockblocker extraordinaire...you know that guy that only talks to girls when they're are standing directly by another guy. Prime minister of FBN.
A person who does weird things, like stares at you while you sleep, follows you through the club, constant DM's, IM's and likes pictures from 3 years ago, or looks at you for hours through a window. Usually a close friend or relative. you know right away if that person is a Creepy Dude or does Creepy things. it is not hard to spot the Creepy Dude.
Also see Creeper, and Charlie Wilson a/k/a Creepy Uncle Charlie
While I was taking a selfie "Creepy Dude" in the background counting my neckhairs.
A fold in one's pants at the crotch that looks like a boner.
No one could shake their gaze from the bulge in Brad's pants. There was a gasp when he stood up to get something to drink, but the tension subsided when we realized he was just sporting a creepy tepee.