[Fungi]

“getting cheek?” Not familiar with that term.

[Texas Eagle]

It’s a common term in Jolly Olde England. I guess we would call it “calling one out” with pointed humor. Probably where we get the term “tongue in cheek”. Saying something without saying something.

[Texas Eagle]

I think CottonBall described it better. Growing a pair. When a timid person finally stands up for himself, even a little, one would say, “you’ve got some cheek.”