Sorry to crash your board, but I understand completely. My little brother is my best friend in the world, and he got married last summer. I wasn't really sure how to deal with it at first, but I had always wanted a sister, and she had to, so I made it a priority to be close to her. The change in my baby brother is amazing - now that he's married we've actually gotten closer. He calls me to invite me for the weekend to stay with them, he asks me to help pick things out for her, I get cool presents from him because they're picked out by a girl...(just kidding
). Things will change, yes, but these kind of changes are good. Try to open up with the girl and become friends. You're in for a really cool type of closeness with both her and your brother.