DH never goes out drinking or taking drugs anymore , he left that all behind in his 20’s before I met him but recently joined a new firm and they arranged a work do at a pub. We had a big family event the next day, we paid hundreds for it with our two little ones and he promised he would just have a couple beers to show his face. Where he never really goes out and he’s older now, I believed him. I woke up and found him in the garden at 5am, drinking a can of cider and remnants of cocaine on him. He admitted he had been doing cocaine most of night and took some home. I told him to fix up as we had the day to do and he was absolutely foul all day. I even saw a number appear on his phone which he quickly hid, so now I’m even concerned he’s cheated. He has a history of texting another woman years ago when we went through a rough patch but never actually doing anything. This all ruined the weekend and he’s still recovering today. He’s said sorry half heartedly but is acting blasé about it all. The fact he’s acting so chill about it it all is just making me angry and upset. Can anyone give me some advice on how to handle this?