What's the difference between a wizard who raises the undead and a sexy vampire?

setup: What’s the difference between a wizard who raises the undead and a sexy vampire?

[BILL undead] lithe, graceful, like always, sings | A fine necromance with no kisses | A fine necromance, my friend, this is | We should be like a couple of hot tomatoes | But you’re as cold as yesterday’s mashed potatoes!

[Shakes, sexy vampire] walking backward | A fine necromance, you won’t nestle | A fine necromance, you won’t wrestle | I might as well play bridge with my old maid aunt | I haven’t got a chance, this is a fine necromance!

(([BILL undead] and [Shakes, sexy vampire] dance the lights fantastic as only a lumbering person can))

[Shakes, sexy vampire] sings | A fine necromance, my good fellow | You take necromance, I’ll take Jell-O | You’re calmer than the seals in the Arctic ocean | At least they flap their fins to express emotion

[BILL undead] | A fine necromance with no quarrels | With no insults and all morals | I’ve never mussed the crease in your blue serge pants | I never get the chance, this is a fine necromance!

(([BILL undead] and [Shakes, sexy vampire] laugh and then walk off))

punchline: One is a necromancer and the other is a neck romancer.