My boyfriend’s brother...

I started beauty school this fall and my boyfriend started college, two and a half hours away. At first we were doing fine, texting and calling all the time. But now that a little time has passed, we talk less and less and our conversations sound like a song playing on repeat. I feel disconnected from him now. I feel all alone. My boyfriend’s brother and I have always been good friends, even before I was with my guy. Since I stayed closer to home, his brother and I have started hanging out more often again. It’s to the point where we hang out every day. A couple of nights ago I ended up on top of him. We only stopped right before actual penetration. I didn’t feel guilty. The only reason I stopped was because I was supposed to... the whole week, all I’ve wanted was to have sex with him. I should feel guilty. It’s my boyfriend’s brother for god’s sake. But I don’t. What is wrong with me?