Yes, but that's assuming Zuko is both cunning and bold enough to pull pranks on people. And while he may be both, he's also too insecure in his own skin to dare and do so against people he's worked so hard to earn the trust of. Nevermind so awkward in spite of his bender's grace that he'd likely fumble and ruin the entire attempt.

"I don't joke." It's said dead pan serious, Zuko's fingers curling around her palm in a dangerous gambit to worm the tips under her hand to pry it off the metal before she rips the railing clean from ship's side.