It's too obvious a thing to engineer, but an accident works out just fine.

(And if he had decided to use such a tactic, he would have spilled on Tony. If you're going to commit to something ridiculous, you may as well go all the way.)

He gets up and checks the closet, for the look of the thing, but finds nothing, which spares him the charade of trying to pull on a Tony-sized bathrobe. So it's back to the couch, where he sets about the business of ridding himself of his whiskey-stained pants.