Garak is plenty interested in this anyway-- not that Weyoun was out all night or even on the roof in particular, but that he was careless enough to be caught doing... whatever he was doing. And then Caro shoots him a look. Oh, why not. If she wasn't going to ask, he might as well. It'll be phrased more politely than if Sullivan has to ask.

"I'm sure it is, but... all night?" Garak blinks and smiles innocently at Weyoun. It's the sort of innocent smile that fools almost no one, particularly if they've ever spent more than five minutes in the Capitol.