love life vs sexual activity

love life and sexual activity both are nouns.

Word	Noun	Adjective	Verb	Adverb
love life	Yes	No	No	No
sexual activity	Yes	No	No	No

As nouns, sexual activity is a hypernym of love life; that is, sexual activity is a word with a broader meaning than love life:

love life: sexual activities (often including sexual intercourse) between two people
sexual activity: activities associated with sexual intercourse

Other hypernyms of love life include sex, sex activity, sexual practice.

love life (noun)	sexual activity (noun)
sexual activities (often including sexual intercourse) between two people	activities associated with sexual intercourse