Did you ask her if you hadn't asked, would she have told you?
One thing I always advise people to do is, in the calm of a quiet moment, decide how many (and what kind of) "strikes" you are willing to put up, in terms of broken no-contact.
Once, but only if she self-confesses? Once, even if you have to ask? Twice? Other?
I'd suggest coming up with a hard boundary in your own mind and heart, and then sticking to it as a matter of personal integrity. Otherwise, you're going to find yourself as the proverbial frog in the pot of boiling water.
