<human>: Can you provide a brief rundown of the text in within 3 sentences?

Hello,

This has been playing on my mind for a long time, and if I ever bring it up we will just end up fighting and hence here I come, to reddit.

Cliffs / summary of the situation

- Was hooking up with a chick (October)

- Things go well, uni accom so spend most of our time together

- We have a semi-serious argument and she goes off and sleeps with somebody else the next day with some random guy from a club. (February)

- We get back together and I find out about this a month or two later. I would never have spoken to her again if I had knew. She always claims it was "to deal with how I made her feel" and that "I figured you were sleeping with other people too" (Not my style) or wtte.

I feel dirty sleeping with her and it really does corrupt the overall feeling of the relationship for me. It was about 4 months ago now and I also have semi-ish strong feelings for her but the knowledge that this happened while her and I were together really fucks with me. I don't know what to do or how to think this away.

Please help Reddit.
<bot>: Gf slept with somebody else 4 months ago after an argument before we were "official", this now troubles me. What do I do?