Question on Phrase

[zh_jiaming]

Greetings, new member here.
Glad to have found this place. I've been studying Japanese but my proficiency is still not where I need it to be.
This phrase I am unable to understand. Any help is deeply appreciated. Online dictionaries often use the english translation "perverse". Google didn't bring up any sample sentences.
へそを曲げる
It seems to be a mix of (へそ = Navel) and (曲げる = Bend) But the context is lost on me.
Thank you

[undrentide]

へそを曲げる (get perversed) and へそ曲がり (noun derived from へそを曲げる） is a set phrase.
へそ (=navel) is considered as the centre of one's body. So having it set in a wrong way, one does behave properly (usually as a result of getting offended or being put off).

[zh_jiaming]

So it is often used in the context of describing someone who is offended?

I'm not sure I really get the part about the naval. I understand that it is the center of one's body. So having it set improperly is a symptom of being offended?

[aardwolf]

Like epigene said, I believe it is a set saying.
I dont know where the "idiom" came from, but there is one that is a bit similar

腹が立つ

they both have to do with the stomach area, but im not sure where that comes from.

[Elizabeth]

So it is often used in the context of describing someone who is offended?
I'm not sure I really get the part about the naval. I understand that it is the center of one's body. So having it set improperly is a symptom of being offended?
Think of a pattern of bodily idioms English has to describe anyone with a "crooked, deformed" personality, as perverse or sulky, "not set right," speaking of their "nose out of joint" "all bent out of shape" "off balance" etc...

[zh_jiaming]

I'll do that.

Thank you for your help.

Deeply appreciated.