During the commission of vaginal sex in the "doggy-style" position, the man sticks his arms out (as a QB would when calling an audible) and yells "Audible brown! Audible brown!". He then withdraws his penis from his partner's vagina and re-inserts it into her anus. This move is perfectly legal when in question of having anal sex since the man has made clear of his intentions.
"Yeah baby, how's that feel?"
"Good, but I've got something better! ... Audible brown! Audible brown! Hutt!"