Hi! I'll be glad to be of help with this issue.
I can imagine how frustrating and hurtful this situation must be for you. You are clearly a good man and a good partner and your girlfriend recognizes she's fortunate to be in this relationship with you. You also felt this same way. And now it's in question. She broke a trust and it's a question in your mind whether she's reliable in a true way. That's not only hurtful, but frustrating: how to know if she can be believed.
And this is actually the key to my answer to you that you need to consider and think about.You are a good person. And you have good values it seems. She shares those values but does have a streak of low self worth. That's true. What does this streak of low self worth do?
Two separate things. It makes her need assurance of her own value. And second it makes her seek that assurance from people outside of herself. The healthy self worth model is that you know who you are, your strengths and shortcomings, and you accept yourself as good, a good human being. That allows you to give of yourself to another person and to receive from another person in healthy ways with healthy boundaries.
When a person has low self worth issues, then those healthy boundaries begin to weaken. She begins to seek reassurance about her desirability and value from wherever she can get it that might feel good at the moment. And then good judgment can fall apart.
This is a rather clinical description of what she herself said occurred and at this time it's reasonable and it happens rather often when there's low self worth. So take her at her word. If this is a boundary issue with her that is more problematic than it seems at this time, you'll find out. But you've been together for quite a while and it hasn't shown up yet to be very problematic. Therefore, take her at her word. What she is saying is believable. It happens often.
You might also show her my answer so that she can work on her own on her self worth issues and not letting the low self worth begin to affect judgment and thus affect healthy boundaries. This kind of self work can be very helpful for her.
Okay, I wish you the very best!
My goal is for you to feel like you've gotten Great Service from me and the site. If we need to continue the discussion for that to happen, then please feel free to reply and we'll continue working on this. If the answer has given you the help you need, please remember to give a rating of 5 (Great Service) or 4 (Informative and helpful), or even 3 (Got the job done) button. This will make sure that I am credited for the answer and you are not charged anything more than the deposit you already made by pressing any of these buttons. Bonuses are always appreciated! If I can be of further help with any issue now or in the future, just put "For Dr. Mark" in the front of your new question, and I'll be the one to answer it. All the best, XXXXX XXXXX