sex activity vs titillating

sex activity is a noun but titillating is not a noun.

Word	Noun	Adjective	Verb	Adverb
sex activity	Yes	No	No	No
titillating	No	Yes	No	No

sex activity (noun)	titillating (noun)
activities associated with sexual intercourse

sex activity (adjective)	titillating (adjective)
	giving sexual pleasure; sexually arousing
	pleasantly and superficially exciting
	exciting by touching lightly so as to cause laughter or twitching movements