So i (25m) have been with my (22f) girlfriend for about 5 years now. About a year ago our relationship changed drastically. She confessed on cheating on me by texting my friend (at the time). I felt devastated & just empty. I guess one day when i threw a party at my house & everyone had gone home already (except him) She decided to text him while in the room with me. (i was asleep) She asked him if he thought she was cute & he replied with yes. She then proceeded to say she thought he was cute too. She leaves the room & sees him in the kitchen, supposedly she went to grab a glass of water & he grabbed her hand and pulled her in for a kiss. She says she pulled away & returned back to the room where i was & that was it. Mind you she told me months after this happened & he had came over to hang out quite a few times after too. So whatever she swears that she told him that it was a mistake and to never look for her again which i call bullshit cause i know she never stops after a kiss (she has a high sex drive) So a year later & im finally ready to let her go. I have tried to forgive her & work things out but nothing is working. I dont trust her & i dont think i even love her anymore. Everything rightnow is just autopilot & fear of being alone. Anyways would it make me an asshole if i wanted to do it back to her? She made me feel so worthless & i feel like she got away with it so easily. I cant have friends now cause i think something might happen again. I cant even go to work in peace without thinking shes flirting with the neighbor or some random guy. Ive been thinking if i should stay with her until i cheat on her the very exact same way she did to me. Is that weird to want? I dont want to hurt her but fuck man she hurt me. I need advice. Should i let it go & let karma do its thing or should i say fuck it & do it back to her? Idk if it will even make me feel better Lol thoughts on my shitty life?