facetious
Definitions
Treating serious issues with deliberately inappropriate humor.
Flippant or facetious in a way that is meant to be amusing but often comes across as disrespectful.
Examples
I was being facetious when I said I enjoyed waking up at five in the morning.
His facetious remarks during the serious meeting were considered highly inappropriate by the board members.
Synonyms
flippant jocular witty sarcastic tongue-in-cheek irreverent playful