What terrible thing would someone have to do for you to key their car?

I am more of a face-to-face confronter.

If someone was doing something that necessitated intervention, I'd more likely key them, not their car. I don't understand keying a car.

you mean I need to have a reason

I was in the military and visiting with out of state tags. Someone from a house down the street mouthed off about out of state drivers, not knowing I was from the state and learned to drive there. I didn't key their car. But late that night "someone" cut all four of their valve stems with their pocket knife.

I have never done it. And I don’t think using a key is all the easy. Use a knife. Paint is strong. I know. I used to do auto body repair

Another reason to drive an older car. Scratch or ding it. No one cares.

I would never do that. I've never wanted to.

Be my ex (just this one specific person)

There isn’t and I wouldn’t.

fail to segregate their trash

I don't do revenge.

Park like a jag and block me in.

Look at my dog

I don't think I would ever. I've got a lot of tolerance for things. If I'm losing my temper I'm probably well past car keying