When during a threesome, he or she takes a mouthful of cum, and then forces it into the third parties asshole via their mouth.
Dude, my girlfriend totally tossed the sauce with our pick up last night!
The act of pissing in her vagina followed by 3 good pumps with your penis pushing the urine out causing her labia to glisten.
Man that Amy is a nasty thot. She loves the Meat curtain sauce toss. I almost vomit each time we do it.