Oh, now, taken literally, that could be awkward.

Jack... well, Jack does know why he doesn't tell his staff that he's immortal, and it's his experiences of being experimented on in the early days. But sometimes it's hard, like when you have to explain the risks you take to someone who offers to share them...

But there's that meaning, and then there's the other meaning.

"Do you think you'd be all right?" Jack says instead, watching Ianto's face.