When a girl is riding on top of a guy facing him, and shes grinding a little to hard for comfort, so the guy reaches around and sticks his thumb up her ass, Fonzie-style. Thrust your right arm out, so the girl cannot see your hand behind her, make a thumbs up, and go for it. Thus giving her both barrels. Or plugging both barrels, both will suffice.
Sheryl was slamming down on Todd's meatstick one night, riding it like one angry jockey, and we're talking really melting his latex. So Todd decided to add a little spice to Sheryls pleasure. He made the happy hitchhiker and double-barrel brian carrolled her