"...actually, yes," Cullen says, after a moment. "You'll have to make it past Madame de Fer, which I suspect is the reason no one else has claimed them. But they look over the garden, so there's that."

Cullen realizes that the likelihood is that Alistair was trying for a poor jest. Unfortunately for Alistair, Cullen is very serious.

(On the off chance it was a serious question, then, there's a serious answer!)