When during a foursome, you and your bro sit back to back like Forrest and Bubba did in the mud, and proceed to destroy your respective females.
Bro 1: "Dude, my girl doesn't want you to see her naked"
Bro 2: "Dude! same goes for my lady"
Bro 1: "OK bro, how bout we sit back to back like Forrest and Bubba did that way we won't see each other or the other chick and we'll call it The Bubba Gump!"
Bro 2: "I just brain cummed"