Lucifer actually jumps. It's not his fault, he was thinking about other things, his mind elsewhere, most of his attention on Gabriel rather than his tricks. So the snake lunges, and Lucifer actually snatches his hand back, and then catches himself doing it.

"Well, that's embarrassing. I think I'm losing my touch."

Okay but that was actually really humiliating.

"You don't happen to have a band aid for my pride in here, do you?"