This really is a sad situation. I got into an argument with a sibling and my mom got involved. I didn't talk to certain family for almost a year. It broke my dads heart. It was a situation similar to yours but not involving a bachelorette party. Just similar attitudes. You want to know what brought us back together? My dads death. Sad but true. It wasn't worth it. Let this calm down some and please reAch out to your brother. Life is too short.