hey, what does the expression "tongue in cheek" mean and where does it originate from? Its one of those things I hear/read all the time, but its also one of those things I never really knew the meaning to.

 

not sure where that originated.

it means jokingly or on the sly. typically it is inserted in a passage where the person is being sarcastic or kidding around.

 

From www.wordorigins.org. I can't vouch for the accuracy of their information, especially considering their lack of understanding of grammar demonstrated by mismatching "one's" and "your" in the first sentence. At least it's something to consider:

Tongue In Cheek
The commonly told tale about this phrase is that it derives from the acting practice of thrusting one's tongue into your cheek to keep from laughing at an inappropriate moment. There is no evidence to support this story or the idea that the phrase comes from the theater.
The phrase dates to 1748 when it was fashionable to signal contempt for someone by making a bulge in your cheek with your tongue. By 1842 the phrase had acquired its modern, ironic sense.

 

I think irony is the key word to describe "tongue in cheek."