A fork of Rural Dictionary
A Slapping Bag is a sleeping bag that you and your girl can fit inside comfortably and still have room to play around.
Bro 1:Me and Jen's sister are going camping! Bro 2: Sweet! Dont forget your Slapping Bag.
A nice pair of tits that are big enough to slap around.
JP, "Joanie is coming over tonight." Friend, "How big are those SLAP BAGS?!?!?!?" JP, "Double D's!!!!" Friend, "sand-dollar nips?" JP, "Nope!" Friend, "I'm so jealous."