Jean-Claude sees the signs -- even if he is not quite familiar enough with the other vampire enough to be able to tell his behavior might be off, the slurring of his words is a pretty obvious tell. Especially knowing that the punch had been spiked.

He shakes his head slightly as he approaches, placing a hand on the other vampire's elbow to steady him as he slows to stand beside him, a fond if somewhat exasperated (these kids and their hobbies these days) look on his face. "Mon ami," he says, gently. "I see you are enjoying yourself."