Usually I find MN mum's a bit precious but this is disgusting and abusive. Anyone who thinks that's ok should replace a gesture with a word or action.
I do words as well (but silently), good god, are you wanting me to say them out loud in front of them? I don't think actually screaming Fuck You to my teenagers is appropriate and that would be abusive!
I also do an action. As I am giving the finger with both hands and silently screaming Fuck You, I make a wilting action with my body. It's absolutely interpretive of how I feel in that instant.
So, given I have a trifecta of gesture, words and action, do I get a prize?
Would you be fine if they did it behind your back?
One day when mine have turned from teenage dicks into normal human beings, I fully intend to tell them what I did to maintain my sanity in those particularly trying instances. I am anticipating they will laugh and say something along the lines of that's so funny, it's what I was doing to you too!
Certain teenagers and toddlers will try you to the limits of human endurance in regards to keeping your shit together (or outwardly appearing to). Some people don't keep it together and do absolutely horrendous things to their children - that's abuse. If a gesture behind their back diffuses the situation and prevents escalation to something that is abuse then its purpose is served.
Some people either don't have toddlers or teenagers that act as the devil incarnate at times or are absolute saints. Good for you, the parent of the century medal is all yours, grab it with both hands. The rest of us are human.