I hope this avoids any further confusion:

The Oxford English Dictionary defines the phrase "tongue in cheek" as "Ironic, slyly humorous; not meant to be taken seriously." Something said or written "tongue in cheek" pretends to be serious in order to make a joke, although the joke made often has a serious point. Perhaps the most famous instance of "tongue in cheek" rhetoric in English literature is Jonathan Swift's 1729 essay "A Modest Proposal," in which Swift spotlights the abject poverty of the Irish people at that time by facetiously suggesting that Irish parents sell their children to the rich for use as food.

"Tongue in cheek" in this sense dates back to the early 19th century, and opinions abound as to its origin. One theory traces it to the theater, where actors, it is said, would thrust their tongues into their cheeks to avoid laughing at the wrong moment. Another possible source is the 18th century practice of making a mocking face by poking one's tongue into one's cheek.

Be well