He... doesn't actually have a good response to that, so he slings back a shot of his own (not hypervodka since he's not going for black-out drunk) and shakes his head. Poor response it is, then.
"Why not pretend? What else is there to do? We can't escape and we can't die, so we might as well drink and frak and do whatever else we can to keep from going crazy." He reaches over to nudge whatever hypervodka is still in Jack's reach away. "Forever's a long time, you know. Things could change."