Youngjae is laughing because of JB's mistake to pronounce Jackson name before the random dance start. 😂 You can watch the full video in youtube. (Sorry to my English)
Even when their practice.. You Are dance.. He can't stop laugh.. Most of this video... Choi Youngjae you are GOT7 SUNSHINE.. AHGASES OTTER SUNSHINE FOREVER.. GOT7 FIGHTING 😍😍😍😍