facetious - fa·ce·tious (fə-sē′shes)

adj.
Playfully jocular; not to be taken seriously; amusing; humorous; frivolous: I was only being facetious, facetious remarks.
Not to be confused with:
factitious – artificial; contrived: His enthusiastic response was factitious.; made; manufactured: a factitious part
fictitious – spurious, fake; fictional; created or assumed with the intention to conceal: a fictitious name; imaginatively produced: a fictitious story https://www.thefreedictionary.com/Facetious