A: Mary said maybe I should grow a beard as well to go with my new haircut. What do you think?

    B: I think she meant to be a bit tongue-in-cheek when she said so.

    Note: This idiom means “in an ironic manner, not meant to be taken seriously.” It clearly alludes to the facial expression created by putting one’s tongue in one’s cheek. This induces a wink, which has long been an indication that what is being said should be taken with a pinch of salt. It may have been used to suppress laughter. “Tongue in cheek” is the antithesis of the later phrase — “with a straight face.” The term first appeared in print in “The Fair Maid of Perth” by Sir Walter Scott in 1828.