My father was like this all throughout my childhood. Many, many special occasions were ruined by him, especially all mother's days.
. He has not changed; in fact, he's got a bit worse as now my DM has to look after him. She should have left him years ago. He was not interested in us children, nor his own grandchildren. He always comes/came over as the life and soul of the party, but behind closed doors it was very different.
Please, for your DC's sakes, if not your own, please have a really good think about the relationship you have with this man. You have said that he has form for this.
It's not your fault. He's built like this and probably doesn't want to change. I know my father didn't/doesn't. it ended up with him being very obnoxious to my DS and my DH. It's only cos of DM that we have any contact with him at all (but she is a bit emotionally blackmailing if I'm really honest with myself). I don't know the whole story, but it has coloured my and my siblings' lives (and not in a good way).
I don't often write on relationship threads and I never say, leave, but please consider your options very seriously if you do not want your DC to have a tainted childhood. They will know what is going on, even if you think they can't hear you.