Jessica poked fun at her younger sister Kyrstal on Instagram!

On July 13, Krystal posted a photo of her standing next to a black dog, in what seems to be a photo shoot set. Soon after the upload, Jessica left a humorous comment calling her younger sister a pig. The exact words of Jessica's comment reads, "Hey pig", with tons piggy emojis.

Netizens reacted to Jessica's comment with laughter, and wrote, "Those 2 are too cute", "If Soojung's a pig, then what am I..", "Lolol what? A pig? Lolol", etc.

Jessica and Krystal are such adorable sisters!