That sounds like something out of one of those fan stories. [a little stab of dark humor, which allows him to ignore how terrifying it would actually be to see Lucifer behind him in a bathroom mirror.]

Could be you're looking at it the wrong way, you know. Could be he does like you, which is why it so pains him to see you off his leash, as it were.

[ah, and on that note - Rincewind bends enough to tap the Luggage on the lid and bid it to open, rummaging for something.]