It's a scary topic to broach directly, which is why he hasn't yet. He's grateful to Ianto for doing it, and doing it so generously. He carries on painting while Ianto's talking, but it's very much automatically. All his attention is on Ianto.
And when Ianto finishes speaking, he's still for a moment, paintbrush still in his hand. Then he turns towards him, an unusually open expression on his face.
"Thank you," he says, and it really does feel like a massive weight off his mind. "That's good to hear. I mean, it's not even an issue at the moment, really, because most of the people I might have wanted to shag have gone anyway." A rather bitter twist of his lips at that, that Kitty should disappear just moments before the rules changed completely. "And even if they hadn't, I don't want to..." He pauses, unsure quite how to say it. "I don't need anyone else just now. It's more, in the long term, you know? If we do end up stuck here for all eternity."