Boyfriend and son

So my boyfriend of 3 years always has negative stuff to say about my oldest son the other day I found out am geting my essure removed and he joked about me geting pregnant again and I said well least my oldest son can watch the baby if that happen and he went completely crazy saying my sons a scumbag and he would never be left alone with a baby my oldest is 17 he’s dealing with adhd and other mental health issues my son and my BF hate each other and now am like this relationship needs to finish as it’s gotten abit toxic my bf is in oz for a year and I am in Ireland he never has anything nice to say about my oldest son any advice on this would be great but think I no in my heart what needs to happen thanks all