i had almost the exact same thing happen to me... broke up, my ex and a friend of mine were friends when we broke up, so about a week later i talk to each of them and say "hey, you guys should get together." i really would have been fine with it. they both swear up and down that they would never do that. actual quote from him "i would never do that to you, you're my friend and you love her. i value your friendship too much to do that to you." find out 2 days later, that they had hooked up the night before. i cut them both loose, end of story. i was far more hurt by him than her. he was my friend, and lied straight to my face.