I have just learnt a big lesson, when dealing with your AH dont use the term 'rule'. I honestly couldnt remember the term 'boundary' at that moment.
My 'rule' (boundary) was that I was not going to speak to him about anything that mattered when he was drinking. He was trying to talk (sneer) to me about how little we have in common, how we werent going to make it till our old age etc but with several beers inside him and one in the hand. As soon as I said 'rule' he flipped. Luckily I managed to repeat that it was my own rule that I wasnt going to speak to him and with this he said fine and walked away.
I mentioned to my adult daughter about this one, as she had left me alone with him and wanted to know how I got on, and she said ' oh, I guess you wont be talking to dad very often then'