It is complicated and, honestly, TJ can understand where Colonel Sheppard is coming from if only from her own points of view. It's difficult to be in a relationship, especially stationed far out, and so you cling to that which you have. Holding back on details, for any reason, is a big deal. It's something she was guilty of (in a Big Way) until it was all too late. Seeing Ianto's conundrum from both sides makes her uncomfortable because she can't give advice that doesn't feel self-serving.

"First of all, I don't think Colonel Sheppard really believes that, but it might be something he's afraid of," she says quietly, plucking up her own blade of grass. "I know you still have feelings for your capt-- for Jack, but. Is that something that might happen?" She lightens her tone. "If Jack said to you, right now, 'Ianto, I shouldn't have left without coming back, let's give it a go' or whatever his version of that is, would you just leave John?"

There, there's his first name. It's difficult, she knows, but putting it out in stark words for Ianto to think about might help him see it from Colonel Sheppard's point of view even better.

Also, she's kind of hoping to meet this Jack, just so she has the opportunity to punt him. Not because he's done anything wrong, but because she dislikes complications. Sorry, Jack.