I regret constantly hitting my little brother when he was chewing with his mouth open at the dinner table. I was about 13 and had developed misophonia, he must have been 5. Our parents didn't understand it. I didn't understand it. I couldn't control myself for years. He was a sweet boy in a poor and dysfunctional family that also fell apart around that time. At the very least, he deserved a better brother.
Decades later, I still get abruptly and irrationally angry when people smack their lips, though I have learnt to suppress the urge to assault the source of the sound.
I can't eat with my Chinese colleagues. I get that more air makes each bite taste better, but it is hard to eat or even focus when your brain is telling you to rip their heads off to stop the sound.
It's an odd curse to live with, as, aside from the situation with my brother, I have otherwise never hurt or assaulted anyone in my life and am generally regarded as a softy. I have to force myself to sit at the dinner table with my mother when she visits, as she still smacks her lips.
Some people smack their lips in quick succession when they taste something new, like how birds drink water, and it drives me up the walls. Slurping is triggering, but not as much. Some people swallow excessively as presenters and will make a "tsk" sound with their tongues before speaking, which is worse than slurping and usually causes me to stop watching the presentation.
I'm glad there is some traction with misophonia research. We need help.