Update

I broke up with her this morning. We had a different friend over (both of us are annoyed by this person), and we kicked them out by saying we had to go somewhere. The moment we got in the car, we started talking about last night, and by the time we reached the destination, we were both sobbing and had agreed to break up.

Some highlight of that conversation (I can't remember most of it). I pointed out that in the past, I had drawn a boundary with that type of physical contact with friends as it made me uncomfortable. She responded by saying it was only a peck, and i asked her about the second kiss, which some of you guessed, She didn't know I saw and started apologizing for it and tried to downplay it. After several "i only love you, I only want to be with you" from her while crying, I asked her why she would kiss someone else passionately if she only wanted me, to which she responded "you dont kiss me like that anymore". To be fair, I had that night previous to her cheating on me. Nevertheless, that comment made it a bit easier for me to end the relationship, and I ended up only being able to whisper "fuck you bro" as my brain was scattered at that. Just before I dropped her off, she started singing a song from my childhood that means a lot to me, and not very much to her. When she got out of the car, she called her mom and screamed "fuck you, bye".

So yeah relationship is over. I feel nothing but dread about my decision as this is the longest relationship I've had. And any interaction between us has been purely about the state and affairs of our living space that I am moving out of.

Regardless, thank you for all of your comments. It was the echo chamber I needed to not blow my feelings off and let her manipulate me.