A sexual maneuver which begins in the cowgirl position. After the man ejaculates inside the woman she gets up off his penis and positions her vagina over his navel. Now he opens her vagina and lets the semen run out into his belly button. This maneuver was named for its resemblance to an otter opening a shell on its stomach.
"Pete, what's an Otterbox?"
"Just give me a second to get the lint out of my belly button and we'll get started."