Jack watches him with definite interest as he continues to sidle closer, slowing while Ianto puts the cup down and then closing the distance between them as Ianto turns back. He wonders how long they've been together. There's certainly a clear degree of familiarity there.
"So, do we sleep with anyone else, or is it just us?" he asks, fairly sure he knows the answer (Ianto's very early twenty-first century) but asking it anyway, as his hands come to rest warmly on Ianto's hips.