Should I break up with my girlfriend?

I realise there's thousands of threads started like this one with almost identical scenarios but I just want to get everything out and hear what you people think. Anyway, here goes: I've been with my current girlfriend for just over a year (we met at uni). I really don't think I've been so crazy about anyone in my whole life, and to me (and everyone else we know) it seems like she feels the same way. However for the past few months, my girlfriend has been texting and hanging out with a guy on her course. She's known him for as long as she's known me but they've always been just friends. It started with the two of them studying together in the library, but it soon turned into them seeing each other out of uni. Sometimes I'd text her to see what she was up to and she wouldn't reply for ages. Then a few days later I'd find out that she was round at this guy's flat. More recently she started going to the cinema him, at which point I told her that I wasn't comfortable about the amount of time they were spending together (bad move, you're probably thinking!). She got a ' bit' annoyed but seemed to understand that I was upset with the situation and said she'd lay off seeing him so much. I thought everything would be sorted after that, but the other week I saw her texting him (she openly texts him in front of me). In the text, she joked about sex or something. Well, a few days later when I was in a 'less-than-sober' state, I stupidly looked through her texts and saw that she'd joked about wanting to have sex with him. I confronted her about it and she was majorly pissed off about me looking through her texts (completely understandable and something which I feel genuinely guilty about). I then said that I was going to break up with her because the past few months have been like hell for me e.g. her constantly lying about where she's been and who she is with. I told her that there's really no point in us being together if she would rather spend time with him than me. My girlfriend then 'begged' me not to leave her. She said that she loved me more than 'anyone in the whole world'. She then said that she was going to make more of an effort to spend time with me. She also said she would talk to the guy about the situation, but I really think she told him that I was being a controlling dick. I'm saying this because whenever we have an argument (only twice in our relationship), she'll end up texting him and complain about me. Anyway, I figured that after we'd talked about our relationship and how she 'genuinely wants to be with me' that things would get better. However, just the other week she asked me if she could say goodbye to her friend because he is going home for the summer. I said that was completely fine and thought nothing of it. But a few hours ago, my girlfriend's flatmate (an honest and close friend to both my gf and I) told me that he saw a text to the guy from my girlfriend which talked about how she really enjoyed the 'kiss' they shared at the museum when they met up last week. So basically I'm at a complete loss as to how to approach this one. I can't confront her about the kiss with that guy because she'll assume that I've looked at her phone again. Also, it seems like she is still in love with me. She makes the effort to spend time with me and text etc. Furthermore, we've been planning to go away over the summer to visit her brother in Spain and despite what has happened she still wants to go with me. So my question is... what the hell should I do? While on the one hand, I really do love her and want to spend every minute of my life with her. I'm also not willing to stay with someone who doesn't feel the same way about me. Thanks in advance for making the effort to read and reply to this, sorry for such a long spiel. Any advice would be massively appreciated :) Posted from TSR Mobile

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