I asked Zen to do a pose I call the, "I broke my neck". Essentially, you just rub the back of your neck as if you had hurt it. It sounds goofy, but it works. Well, Zen was doing this, and doing a good job, but I asked to smile saying, "You broke your neck, but you liked it". This smile was him genuinely laughing at that, and it was our favorite joke throughout the rest of the night!