Me (ftm) and my gf (mtf) have been together for four years. Since the beginning we agreed on NM without much rules (a beginnerd mistake) except that we agreed on transparency and honesty about getting involved with other people. But recently, in the last few months, she lied to me three times about relationships.

The first lie was when she was going on a date with a crush of hers that she had kissed once. She said to me she was going to dinne with a friend when she was actually dinning with this date. In the end her crush didn't wanted to kiss her and they just talked, but the lie really hurted me.

The second lie was about beign romantically involved with another girl (who has a monogamous boyfriend and is cheating on him with my gf). The meet once at the time and just kissed, but they had been talking online about sex and romance over three weeks and I didnt even knew they were friends. One day she felt guilty and told me all of it, but I felt really betrayed as she broke our only rule of honesty again.

After this I wanted to set new and more clear boundaries about our relationship, but she was cold and resitant. She was scared I would forbid her to see her lover and didn't acknowledge my feelings and needs. After almost a week of arguments she realised she was beign unethical, she apologized and we agreed on a few rules.

No sex with other people in the moment (we can revisit that later if needed), we can kiss people ocasionally in parties without prior communication, but we do need to communicate about dates and romantic involvement with other people.

Then after a while she told me they would meet again for lunch. After she came back home I asked how it was and what did they do to wich she repplied "we just talked and drink some juice". But recently after some talking I realised they did kiss that day and she omited this information. She sayed she didn't realised she was lying and thought "it was implicit" wich is just a way of omission.

And now I am having a real hard time thinking "how can I trust this person that doesnt even realise she is lying?"...

She acknowledge her mistakes and says she wants to change them, and I also am aware on my part on making her feel insecure on telling me the truth (I am asd and have severe anxiety and cry hard when much distressed). But that wont work if I cant trust her...