When I was in college, there was a party that I went to for my team and I for one reason or another wasn't drinking.
I sat on the stairs in the center of the place (huge old house), and a guy on the team came up with his shirt off - he was a pretty ripped guy. He was drunk and he wanted everyone to say "wow, dude, you are so cut" and the girls would rub him.
Then, to draw even more attention to him, he was carrying a permanent marker around with him and asking people at the party to sign his back.
He handed the marker over to me and turned around and said "Make it big!"
So I wrote out in block letters across his upper back "I AM GAY".
He then thanked me and strutted off to the dance floor and turned his back to the crowd, screamed out a "Wooooooo!" and thrust his firsts up into the air which turned into thumbs pointing to his back in a "damn I am cool" sort of way.
Everyone turned to check him out and the rest is history.