Issues w bro.. long post so sorry!

So long story short my brother is known for being a flake but we wanted to give him the benefit of the doubt at the wedding. We got married about two weeks ago, last minute he cancelled on the bachelor party (normal occurrence).

The day of the wedding he was late to the venue even though he had agreed to be there at a certain time. Was about 20 late, not horrible but still crappy. Then he got high during the wedding which is a huge deal since my Husband is a recovering addict and we had explicitly said several times that there would be no substances at the wedding. He brought his gf that my family doesn’t like but she’s nice enough so whatever we were happy to have her and try and spend more time with her. i then found out that he wasn’t even with the guys getting ready and was just hanging with her until a tiny bit before the wedding which made me upset. they live together and see each other everyday but we never get to see them so we thought itd be a nice time for my husband and him to get to hangout more but no. There were plenty of SOs happy with doing their own thing or hanging out with us girls while we had to be in separate rooms but apparently he couldn’t be away for very long. Then on top of it all he left the wedding super early, before a lot of the guests.
Normally i would just say forget it because i don’t see him very often but since the holidays are coming up i know we will have to spend time with them and i’m the type of person that has a hard time acting normal if something is really bothering me.

I guess i’m looking for advice on what to do and how to have a conversation (ie what i should say/ verbiage)

so sorry for the long post, any advice is appreciated!