I'll keep this on the short side. My gf lent me her computer to do some work since mine stopped working. The messages app popped up, and curiosity got the best of me. I searched my name and found out she fucked another dude about two weeks into dating me and lied about it to my face on many occasions. She also lied about the time frame of someone else she was seeing simultaneously while we weren't "exclusive" which was something I honestly never knew people actually did. I was always under the notion that you date who you date, and that's it, but I kept an open mind until now. In addition she sort of encouraged her best friend to cheat on her long term boyfriend, and asks if her friends/family think if she's "out of my league".

I know I was wrong, but I was genuinely thinking about marrying this girl. She's not currently cheating or anything, but I can't help but feel that the illusion has been shattered. These messages were fairly old. Could she have changed in the past few months? I just want this to stop hurting so much.

Edit 1: Thank you for all of your advice. I'm in a weird place and really want this to work. Let me clarify some things.

She fucked the dude before we were exclusive. She expressed to me that she had issues with committing at the time but never told me about the hookup. I asked about it recently, and she lied like she had every time I asked.

In addition to all of this, we had a pregnancy scare early on. It was early enough that this other dude could have been the cause, but again, it was never mentioned.

As for the cheating best friend's boyfriend, he knows. It's super weird, but they're working on it. That's all the info I have on the matter.

She has also stated to her cheating friend that she fucked all of her male friends and didn't tell me about it. She said it in a context that was encouraging her friend's infidelity. I'm not sure if this was even true. It almost sounded too ridiculous, considering I know her close male friends and asked if she fucked them which she denied. Maybe they were her other male friends. She has told me about a few she slept with.

She has changed. I don't think she has ever been loved for reasons outside of her looks before. I have seen it in the way she acts and communicates. She has definitely grown. I could be an absolute copium smoking dolt for thinking this, though. Idk

Edit 2: Thanks for the input, everyone. I'm going the communication route. I want to give her the chance to explain herself. I have known her and her family for years, and they all have been kind to me in times when I had no one else. It's just tough bc I'm away for the next week and a half. This feels like a conversation that needs to happen face to face. I guess I'll just play it cool till then.

P.S. I don't need advice from incels. If you're just here to bash women, take your advice elsewhere.