I declined to help...but I didn't realize it was a serious request

[Onyx_TKD]

I think this may be a similar miscommunication to the "request disguised as a question" topic that's being discussed in another thread.

The OP's friend said jokingly that they were going to head home "unless you wanna come help paint." I think this question could be interpreted in several different ways:

• "Do/did you want to help us paint?" i.e., literally asking if the OP wants to/would enjoy participating in the painting, without indicating that her help was needed. This is the question the OP responded to, with the honest answer "No, I hate painting."
• "Would you help us paint?" i.e., the friend was using the "do you want" format to make a request, as discussed in the other thread. A response of "No, I hate painting" would imply that the dislike of painting is prioritized over the desire to help. (There are perfectly valid reasons to refuse, especially when the request is sprung unexpectedly at 9pm, but a bald "I hate painting" as the reason for not helping would probably seem a bit callous.)
• "Do you want to help Annie?" This is the least literal interpretation, and the one to which "I hate painting" as a reason for refusal would be most hurtful.

Personally, I think the literal interpretation of the question makes the most sense, given the joking context and timing. The OP had been given no indication that her help with painting was needed or desired; it was late; the situation was not one where the OP would be prepared to go paint even if she wanted to, and the context indicated that everyone was about to head home unless the OP "wanted to help paint." I would interpret that as saying "Yeah, we're done for the night. Unless you're just dying to get out there and paint--you can if you really, really want to.  " Instead, Annie seems to* have taken the answer as a response to interpretations 2 or 3, i.e. declining to help her, rather than denying a burning desire to paint at 9pm. There are obviously people used to phrasing requests in the "do you want to" format, so I see how she could feel a little hurt if that's the way she understood the conversation, but IMO she should recognize that the OP gave a perfectly reasonable answer to the literal question asked.

*"seems to" because of the second-hand account of her reaction.

[SoCalVal]

I think asking someone to help paint at 9 at night after dinner (and what sounds like a work night) without prior notice is pretty rude. You did just fine, Raintree.

I don't think asking someone as an aside to help paint at 9 at night after dinner without prior notice is rude.  However, I think not only expecting the answer to be yes AND getting offended when the person says, lightheartedly, "No, I hate doing that" is pretty SS and rude.

The time to ask would've been when she got the invite for dinner, not just as they were parting ways after dinner.

[Bijou]

I would have taken it as a joke, too.  Knowing Annie is a person who talks behind her friends' backs, I wouldn't give her complaining about it to others a second thought.  Now, I would wonder about someone who felt they had to tell me she was talking about me behind my back.

I'm the world's worst painter and my husband has to go over what I do most of the time so that would be why I would always decline to help someone paint.