cheating vs sexual activity

cheating and sexual activity both are nouns.

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

cheating (noun)	sexual activity (noun)
a deception for profit to yourself	activities associated with sexual intercourse

cheating (adjective)	sexual activity (adjective)
violating accepted standards or rules
not faithful to a spouse or lover