The unbelievably brilliant dance that Stefan Olsdal, of the equally brilliant band Placebo does on stage, often but not limited to the song Taste In Men. I think he might have been gay dancing a bit during Protege Moi at Wembley 2004 but I'm not sure, I couldn't see very well....
The gay dance involves a lot of hip swinging, arms in the air and general sexual energy. Ask any Placbeo fan about it and they'll probably give you a demonstration.
Someone: "Oh you really should have been there, I was right infront of Stef while he was gay dancing!"
Someone else: "ugh you're so lucky!"
Stefan: *gay dances*