impropriety vs sexual activity

impropriety and sexual activity both are nouns.

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

impropriety (noun)	sexual activity (noun)
an act of undue intimacy	activities associated with sexual intercourse
an indecent or improper act
an improper demeanor
the condition of being improper