[Fern raises his eyebrows, not having expected to receive an actual punching offer. Especially one that might satisfy his whole 'wanting to punch the town' urge. He smiles a little at that.]

Hah, really? That sounds pretty great. I might have to take you up on that offer when you're done.

[He gestures at the roof they're on.]

I don't wanna take you away from your work.