Those perfectly defined butt cheeks with the crease at the bottom. So the cheek pouches over the crease creating a "fold over bun". This creates a religeous effect when the woman is viewed from behind, while standing, from bun level.
A ball fold over is where the base of your penis meets your scrotum. You can't see the ballfold-over because hidden by the cock.
"I totally got some lint on my ball fold-over the other day"
"I like it when she performs oral sex on my ball fold-over"
"mmmmm mmmm....mmmmMMMMMM"
"My ball fold-over is sore from gyrating"
A prank in which the prankster, in a public restroom, poops into a newspaper, folds it back up, and leaves it in the stall or "bay" for a future occupant. The future occupant then picks up the paper after settling in, and opens it to find human excrement.
Mr. Williams, don't use bay 2. One of the guys on our team left a foldover in that one.