You were only in the club after being mistaken for a boy, the club knew you weren't a boy but the clients did not.

Hikaru: "The girls are gonna go wild for this."

Kaoru: "Yeah boss this is gonna bring in good business for the club!"

Tamaki: “NOOOOOOO! DON’T DO THAT TO MY SWEETUMS! GET THAT BUNNY COSTUME AWAY! YOU’LL DESTROY THEIR INNOCENT SOOOUUUL!” He wails dramatically whilst trying to drag you away from the twins.

(This is one of his regularly scheduled meltdowns)