<human>: Our parents are extremely good friends so I've known this guy almost my whole life. We're not interested in each other romantically and on my side at least I'm not attracted to him at all, but we've been through a lot together - tragedies, celebrations, etc.

We moved to different states for college but stayed in touch.  He started seeing his now-fiancee, who was uncomfortable with me at first.  At her request we stopped talking as much as we used to and my friend showed her any text conversations we had.  When we talked using Skype or VOIP it was only when she was nearby.  After a while she relaxed and the 2 of us eventually became friends too - she asked me to be a bridesmaid in their wedding a few months from now.  She's a great woman and I'm happy for both of them.

Now, about the argument.  Our families got together for Christmas and New Year's and it was also the first time in 2 years I'd seen my friend in person, so we spent a lot of the time catching up and hanging out with our cousins like we used to.  We weren't trying to exclude his fiancee but looking back, that's what happened.

Yesterday she sent me a picture of herself with a black eye and said it was from my friend.  She also sent me screenshots of texts where he kept apologizing, said he overreacted, and begged her to talk to him.  Apparently they'd been arguing about the way he ignored her during the holidays and he'd punched her after she said she didn't want me as a bridesmaid anymore.

I told her I'd be there if she needed anything.  Idk what to do about my friend, this doesn't sound like him at all but when I asked him about it he said everything was true.  He sounded extremely torn up about it but I won't see him the same way ever again.  I've asked him not to contact me until everything with his fiancee is settled one way or another, but otherwise I'm struggling with what to do.

Give me a shortened version of the text
<bot>: Lifelong friend punched his fiancee in the face while arguing about his actions during the holidays, how to deal with this?