Night vision. Part of the vampire game but if he notices Jack heating up he's not saying anything about it, just nods in agreement.
"We're good. And for what it's worth, I offered to pretend like this whole thing never happened. If anyone should get credit for this, it's Ianto."
This nice moment of reconciliation, whatever the future might bring now that they've cleared out all that old nasty business... good things, he hopes, cautiously optimistic now that he's talked to Jack. Such a nice moment. It'd be a shame if something ruined it.