make her upper lip curl

[sarasara]

I do not understand "make her upper lip curl" in the sentence
"The thought (...) had the potency to make her upper lip curl..."


Could someone explain it please? I tried several dictionaries, thesaurus etc but failed.
Thanks a lot,
Sarasara

[belly_ttt]

You should give the whole context

[beascarpetta]

"The thought (...) had the potency to make her upper lip curl..."

meaning that thinking about (...) made her feel only contempt for...
go there

[Anglika]

It is a facial expression where the mouth tightens and the upper lip becomes more prominent. People are usually totally unaware they do this.

[RonBee]

I do not understand "make her upper lip curl" in the sentence
"The thought (...) had the potency to make her upper lip curl..."


Could someone explain it please? I tried several dictionaries, thesaurus etc but failed.

It seems to me to have something to do with sex, but isn't there some context for that?