He knew that question wasn't supposed to shut him up, or send him into some kind of internal overload, but he didn't know if there was anything about him that Cassian didn't already know, it wasn't as if he kept things to himself, really.

Though after a moment he said: "I never calculate the probability of your death before a mission, only of your survival." Which were two different things as far as Kay was concerned, and something oddly superstitious, for a droid. But it probably made a certain amount of sense, considering that Kay had never done any of the borderline religious things that other droids did, thanking 'The Maker' for things, that corner of his consciousness -however manufactured that consciousness was- needed something to do as well.