Somehow, in the midst of talking about Gwen and her potentially moving in here, Jack had managed to both say and do the wrong thing. However, what that thing was he didn't for the life of him, know what it was or how to fix it.
He saw the look on Ianto's face and heard that note and realised he'd done something. Unfortunately for both Jack and Ianto, the words 'I'm sorry' didn't exist in Jack Harkness's vocabulary. The best he got was implying such and moving on without really talking about it. "It is what Gwen thinks and does that bother you?" Jack asked, rising from the sofa and moving towards Ianto. "What else is there?" He asked again, watching his lover carefully. Because, truthfully, Jack was at an absolute loss right now. Possibly because Jack didn't do relationships, at least the ones where he had to talk out what he and his partner were.
Twenty-first century, Jack, he had to remind himself. Twenty-first century.