I just found out my [35M] girlfriend [32F] tried cheating on me eight months ago

Hi

I’ve been with my girlfriend for a year and a half. A year ago she moved into an apartment block and had a large group of friends before falling out with them last year.

Eight months ago she saw a guy outside of the block while we were walking back to her apartment and it seemed really tense. I met him previously a couple of weeks prior.

He sheepishly said hey to me and I said hey back. My girlfriend ignored him and looked awkward. I asked what it was about and she said he told her he had feelings for her. They had a big fight five months ago and hadn’t talked since, she said he just got weird. I believed that to be true until last week.

Last week he sent me a message to say that she just tried reaching out to him again and that he’s done tolerating her behaviour, and she got angry when he refused to do things on her terms. His version of events were:

Eight months ago she told him the relationship was effectively over and then tried grinding on him at a bar, biting his arm, pinching him and holding his hand. On the same day I saw him, she was flirting with him in person four hours previously.

Even after I saw him, she kept flirting with him and even went as far as sending him a picture of the bed in our hotel room. She also sent him voice notes about our relationship problems at the time that she hadn’t even raised with me. At that point he became uncomfortable and distanced from her, and she became verbally abusive before ending their “friendship.” He then had to get therapy afterwards.

He forwarded texts and voice notes from her that confirms all of the above. I’m generally really confused because this is such a polar opposite to the person I know. Since then our relationship has developed and gotten stronger, but I’m struggling to overlook this.

I spoke to her about this and she completely freaked out and went silent for four days. She’s now saying she was convinced the relationship was over because we hadn’t seen each other for a while, and her autism makes her misjudge social situations. She said she only got in contact with him because he was a good friend and she wants to be civil.

While I know she has autism quite severely, I don’t think it explains this….this is a deal-breaker isn’t it?

TL;DR My girlfriend tried cheating on me eight months ago and completely lied about it. The person she tried cheating on me with refused to go through with it multiple times and she got in contact with him again recently and I’m not even sure if I believe anything she says at this point.