Baiting the exploitation with that title, "Necrofilia" is all-sex porn gussied up with a gimmick: mourners at a gloomy wake having sex with each other including an old geezer fondling the corpse and fantasizing having sex with her (Erika Bella is the lovely deceased woman).
There is no dialog, just boring voice-over variation. And the XXX content is the epitome of mechanical sex: women generally performing with their eyes closed, and the guys as solemn and stolid as when they're just sitting around as mourners.