Do tail twitches/thumps always mean "annoyed"?

[camellian]

My new foster cat twitches his tail while I'm petting him. He'll be stretched out on his side, purring and tail going "thump thump thump" on the couch...

The only two meanings for a twitching tail I know are "I'm hunting" (he's definitely not) or "I'm annoyed". I'm particularly aware of the latter because I once knew a cat whose twitching tail was the only warning you'd get that she'd had enough petting before she'd sink her teeth into you (for some reason she found biting preferable to just getting off of your lap).

My foster's tail-thumping starts up right away as soon as you start giving him attention. He'll be stretched out on his side, purring, and by all appearances enjoying himself... except for the twitching tail. Is he expressing annoyance, or are there other meanings for a twitching tail?

 

[mani]

It often, as you know, means annoyance and, as you found out, is a great indicator to stop petting.  But if your boy doesn't attack, I think it may just be something he does.

I have a girl who wags her tail virtually all the time.  She's quite thin and people joke that it's all the tail exercise she does..

If he's not attacking, I'd just play it by ear and watch out for any other signals.

 

[lilin]

I think that sometimes this can indicate they're getting wound up, not necessarily annoyed.

My kitty will do that and then nudge me into petting her more firmly. I think, for her, it's her working herself up into play mode. She obviously wants me to keep doing it, and at some point, we move to play time. She's a youngin' with energy to burn, and I think for a lot of cats, firmer touches stimulate them in a way that can either mean "playtime! roar!" or "ugh, stop it!" or maybe even something else entirely depending on the cat.

I don't think all cat behaviors will mean one thing in all cats, so the most important thing is to know yours and pay attention to the other stuff they're doing.