He should have know Jack would know he exact amount of time it’s been. He suspects once upon a time he could have rattled off the same statistic about Ianto himself. When you’re eternal what else can you define things by except time.

“I’m sorry.” It won’t help but in the end what else is there to say? He knows Jack will understand what he means, that he can see how hard this is, how much he’s lost over the centuries and how painful it is to add more names to that list.