sexual activity vs cheating

sexual activity and cheating both are nouns.

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

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

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