My ex is being a complete jerk. ?

My ex boyfriend broke up with me 3 days before Valentine's Day. He told me that he wanted to remain cordial so we did and still hugged and chatted every now and then. However, the other day while walking in the hall he saw me and began cuddling up and holding hands with some girl. Immediately after that he came over and began trying say she was just a "friend". Late that day whEn I walked past he got into an altercation with my friends and stated they need to stay out of our business and stfu. Another day while I was very obviously walking behind him he began feeling all over another one of his "friend's" butts. He got upset with menwhen I refused to give him a hug a few minutes later after witnessing that. Personally I think all three of his actions were very disrespectful, especially the last one. I understand we are broken up but at least repsect the other ex and their feelings! So, should I confront him about the situations or let it go and continue to talk to him as if I'm ok with it, since we technically aren't together anymore.