When you find out a girl has
already slept with a close friend. (
male or female, it's still beef)
See Tainted Sausage for a
man.
Dude 1 'Bro I was gona sleep with Chloe, but then I found out you
already had'
Dudette 1 'Ah man that sucks, doesn't matter though, she was tepid at best'
Dude
2 ' When a friend taints your prospect beef it hurts hard, ahh... Tainted Beef'