A rugby/boarding school game. All male participants gather round a digestive biscuit and masturbate. The loser is the one who cums last. His forfeit being to eat the said biscuit. Also known as soggy biscuit.
Posh Kid #1, "Hey, Rupert, fancy one of our spiffing games tonight?"
Posh Kid #2, "Rather Percival! How about a game of digestive biscuit?"
Posh Kid #3, "Excellent! There's no way I can possibly lose four times in a row!"