My (26M) girlfriend's (25F) neighbor hit on me. How should I tell her?

I'm in a 9 month relationship with my girlfriend, which is the longest by far I've ever been in a relationship with a girl. I've moved in with her recently. She seems to be changing a bit and I don't like it. It's probably not big stuff for most couples, but it is for me.<br><br>My girlfriend seems to be very critical of me and it is affecting my confidence. It is to the point where I don't even want to speak any more because I'm afraid she will pick apart whatever I say. I don't know what to do. Do I bring this up with her? I'm afraid that if I do it will only make things worse.<br><br>HAPPY UPDATE<br><br>First off, thank you so much for all the positive advice. It's really meant a lot to me. I needed to hear it from some strangers on the internet for it to really sink in. <br><br>I texted her and asked her to come home as soon as possible. She asked me what was up but I said it was nothing urgent. She is usually out and about with her friends a lot. To my surprise, she came home almost immediately. I could tell she was really surprised I asked her to come home and she was really curious.<br><br>I showed her my chambers post. I read it out loud to her. She was listening really closely. I asked her my questions. She said "Of coarse I will always love you. You're such a wonderful man and I really love you. It doesn't matter where you live or who you hang out with." She seemed genuinely shocked that I even asked her. She really didn't seem too mad that I asked her. She seemed a little surprised at my list of grievances but seemed to agree with them.<br><br>I told her I was really sorry to doubt her. She said it was fine and that she never saw this coming at all. She said she loved me too. We talked a lot about things and then we had sex. I'm really glad we had the talk. I clarified a lot of things. We've finally had our first serious talk as a couple and we are on the same page.<br><br>She said she was going to give me space if I wanted it, and she said I don't have to tell her about every little thing. I said it would be nice if she would do the same thing for me though. She laughed and said she has always kept some things private from me. She said she doesn't like to tell me every little thing she goes through because I seem like a "private person". Me?? I felt like I needed to tell her every little thing about myself. I felt like she needed to know. She said she's never even told me what she does at work every day. I started feeling a little bad. She said she was finally going to tell me about her day at work yesterday. I was really excited to hear. She told me about all the different meetings. It was really interesting and I enjoyed finally learning about what she does. <br><br>I'm really happy. I feel like a huge weight has been lifted from me. I'm really glad we had the talk. She really seemed to understand were I was coming from. I'm so glad she isn't mad at me and is willing to work though this with me. <br><br>It's too bad some people aren't as lucky. I'm probably not going to post any update to this. I finally feel like I can move on with my life. <br><br>TL;DR: I read my chambers post out loud to her. We talked a lot. We had sex.