So that's what it looks like when he shoves his feelings down and puts on a smile, huh? Okay. Vash considers Vash for a moment, then reaches over and smacks him on his remaining arm.

"Stop that! Whatever you're thinkin', stop it!" He didn't miss the grip on that missing arm, and he's certainly made the connection already between this Vash's missing arm and the Vash back at the station house with the pretty green hand. Whatever happened there, they don't want to tell him and that's fine, but there's no way it's a good reason to stay away from Rem! She's Rem. She'll forgive anything. "You don't have to stay if you don't want to, but if you want to, an' you're just being stupid, then stop it."