Well, it's quite understandable why you don't trust someone who is untrustworthy. Lying, excuses, being with you before she left the last one. Someone who doesn't know right from wrong and apologizes for being disrespectful by feigning ignorance is untrustworthy because they have no simple, fundamental personal boundaries. Fly-by-their-ass type people do and then say sorry. They learn nothing about relationship respect and common boundaries until they cross them. It's up to you if you want to be hearing "Oh, I didn't know that was something I shouldn't be doing while in a relationship AFTER it's already been done.
One's partner should compliment their already happy life, certainly not cause anxiety and fear within while waiting for the other shoe to drop.
In future, don't ignore the fact that you asked someone to be exclusive with you and they hedged. There is a reason fro that hedge and it's usually NEVER very good for the one being hedged upon. Be true to your own personal boundaries or learn to keep it casual if you're going to drop them.
Adding: Tell us, did she ever actually agree to "something serious" as you put it or did you just take up where you left off after she confessed to doing her ex?
Last edited by Wakeup; 22-04-13 at 12:09 AM.
“The willingness to accept responsibility for one’s own life is the source from which self-respect springs.” ~Joan Didion