Is there a specific word for the condition of deliberately reacting against someone else's behaviour because you they get on your nerves?

[Tinker]

I'm thinking there should be good German word to describe, for example, becoming very moody and monosyllabic when you're with someone who won't shut up.

Deliberately taking a stance on something which isn't what you actually believe but just because it's the opposite of whoever you're talking to

God, this all sounds a bit heavy now - it's meant to be more light-hearted than it sounds.

You are just being trotzig, Poledra.

i can't believe it actually has a name.

Ooooh, that's a good one for my next discussion with DD1 'Don't you oppositionally defy me, young lady!'

Oppositional Defiance Disorder - Yes, I like it.

Can recognise most of those symptoms. Only with people who get under my skin, invade my space (physical and emotional) eg current object of my ODD suggested (entirely reasonably and kindly) a rememdy for ongoing minor "affliction". Normal repsonse of a non-ODD person would be "Oh, thanks, that's interesting. How does it work? What's it called. Gee, thanks, that's really kind of you". ODD responce "Mmmm, oh" all said with a tight fake smile.

So, official new name can be trotzig?

So, it can be quite passive as well as overtly aggressive. Covers all bases

Think it's best if it tends to the passive and ostensibly reasonable but is actually evil for the sake of it just because the person is a twat...