sexual activity vs flirt

sexual activity and flirt both are nouns.

Word	Noun	Adjective	Verb	Adverb
sexual activity	Yes	No	No	No
flirt	Yes	No	Yes	No

sexual activity (noun)	flirt (noun)
activities associated with sexual intercourse	playful behavior intended to arouse sexual interest
	a seductive woman who uses her sex appeal to exploit men

sexual activity (verb)	flirt (verb)
	talk or behave amorously, without serious intentions
	behave carelessly or indifferently