Well ...let's see Mum:
Seeing as sarcasm is passive aggression....and since I'm not emotionally involved with your x.......
It probably wouldn't been too hard for me to deal with him, depending on certain circumstances (I mean...if I senced a reason to be afraid of him...it might be a different story).
I find it a whole lot easier to come up with what seems like the right thing/s to say when I don't have any real emotional connection to a person. I can think clearer without letting my emotions interfere as much.
Often...when I just don't know what to say....I'll just agree with them and it shuts them up. How can you argue with someone who's agreeing with you?
And if I agree in such a way that anyone listening would probably laugh....well then....it works for me.
Sometimes though....I am so shocked

or confused by what is being said...that I feel totally at a loss for words.
I was taught: "When in doubt....say nothing".
Or, when you totally do not agree with someone but you don't want to get into a struggle:
"Oh really??" is a good response. Indicate you don't believe a word, when the correct tone is used. They will just keep on talking and talking and you can just keep on saying: "Oh really?". Sometimes, they get the message.
Wellllll...that's the end of my tricks. After that......I haven't got a clue.
I still love the joke I heard recently......
Look the person straight in the eye and ask: "What sex are you?"
And then laugh like heck, when they answer!!!
Get's 'em every time.
GFN