Friend annoyed at me because I hate her boyfriend, help?

I know what you're going through, he sounds insecure about it, don't dog on him, and don't complain to her about him, he might be a little of a jerk but since you guys used to like each other you have to somewhat understand where he is coming from.. don't worry the girl ALWAYS take the boyfriends side, it's normal. What ever you do don't come between them. Try to ignore his immaturity and if you get a text that doesn't sound like it's her, ignore it. Don't let him get to you and don't talk negative about him to her that will only make your guy's friendship go down the drain