This term is used a lot when playing street basketball to imply that you shouldn't get to close to the person you are trying to block. Me and my friends say it when someone you're talking to gets to close to you or is invading your personal space.
A girl is at a bar and a guy walks over to her to make a conversation by getting really close to her face with his face and his breathe really stinks.
Guy:"Hhhhhey beautiful. Hhhhhhhow are you tonight?"
Girl: "Hey man! Three feet no check!" (As she puts her hand out and pushes him out of her face)
SOmeone who you dont like. i call them a dusty feet because of there dirty mentality and personality. and/or if they have dirty feet or shoes that they wear eveyday to school!
If you see a girl that looks dirty you scream out loud "DUSTYFEET, PLEASE DONT BOTHER ME"!! LOL =)
A person who, when turned on, gets rather sweaty or 'drippy' feet. They often smell, or when wearing just socks can ooze.
Alternatively it can just be used to describe being turned on or someone who's turned on.
'Oh my, we were just about to get down to business when I noticed Will's Drippy Feet.'