wouldn't you feel soo much better though if you knew, you have a right to know you should tell her to just tell you and that you wont do anything to him (at least that way you will know who it was).

And its his fault aswell unless he didn't know...

Which in that case why would you want to kick the shit out of him, because its not as bad if he didn't know, if it really was her fault find out who it was. (not saying you should just saying that you might feel better knowing who it was).