Cooper can hear the pause in Joss' words when he mentions Nancy. He can think of several substitutes that he was probably thinking, none of them flattering. Still, he's not going to solve anything by picking a fight. They'd already tried that in the entryway. "Well, you got the luck of somebody on your side." This could have turned out with Cooper reading Joscelin's obituary in the London Lambast Daily.

"So are you gonna retaliate against that witch?" He can't very well stop him, but they both know how JC's been wanting the Nest to play nice with everyone else.