Impetuous1

Yup that statement does say a lot. Leave her. You don't sound possesive to me either since , although you admitted your jealousy, you did not try to control her. It sounds like she's just going to cause you a lot of unnecessary heartache. Life's too short to put up with that shit. Believe me, I've been there. From that statement she made to you it sounds like she likes to flirt a lot with her male friends. That's not a problem as long as she knows when to stop and can tell who not to flirt with, if they seem to be taking her seriously. Either she couldn't tell that this dude liked her (unlikely) or she had the hot's for him and let it continue in the hopes that it would lead to where it lead to. She needs to figure out what she wants. You don't have to wait around for her to decide. Like Toaster said there may be more that she's not telling you. But do you really want to agonize over that? If you do stay with her, let me tell you it's a long, steep, slippery and incredibly long road back to trust. It's 3 steps forward and two back anytime something out of the ordinary happens. Too much trouble to do more than once if you ask me. Not to mention that you sometimes get this horrible mindset of "I owe you one now". Best to break it off cleanly and avoid her for about a month or so. Just my opinion.