When you make a tongue-in-cheek remark, you do not expect your listener to take you seriously. Although you may look serious, the intention is to be humorous. What you say is meant as a joke.
*Was Vijay speaking with tongue-in-cheek when he referred to Sania as the heartthrob of India?
*”We all know that Raju is an intellectual”, Bala said tongue in cheek.