When straight dudes feel, by virtue of their strong heterosexual presence, that they will bring superior straight vibes to an otherwise perceived-to-be-gay place. Opposite of Gay Up the Place.
Straight Dude #1: Let's go to Club X8@y& tonite.
Straight Dude #2: I'm down for it. We'll straight up the place!
Straight Dude #3: O fosho, that place be gayer than gay.