His expression warms a little, almost imperceptible in its particulars, but clear enough for someone even as familiar with his demeanor as Abby. "I haven't so many friendly relationships in Riftwatch that I am inclined to be extravagant in throwing them away," is, in fact, a joke in delivery (if somewhat true in content). Less of a joke, though, when he adds: "I trust you. It is not something to be undone that way, in a moment."

He's known before now that being friendly with both Abby and Ellie has meant navigating the bad blood between them. If he knows a little more of why, now ... it's still only a little. For him, it doesn't truly change the situation much. He's as relieved as she is that this needn't shift how they interact.