sex object vs doer

sex object and doer both are nouns.

Word	Noun	Adjective	Verb	Adverb
sex object	Yes	No	No	No
doer	Yes	No	No	No

As nouns, doer is a hypernym of sex object; that is, doer is a word with a broader meaning than sex object:

Other hypernyms of sex object include actor, worker.

sex object (noun)	doer (noun)
any person regarded simply as an object of sexual gratification	a person who acts and gets things done