To cement it in my head: "Le mie sorelle" (my sisters) is plural, so the plural verb "amano" (they love) is used. Also, the direct pronoun "lo" (him) is used before "amano". Okay...got it.

Why is it l'amo but lo amano instead of l'amano?

My sisters really love him?

so "Lo" is "it" ir "him" ?

It could also mean "it"