SEE ALSO: Lee Hwi Jae's twins and Song Il Kook's triplets show their hearty appetites in still cuts from 'Superman is Back'

During the recording for the episode, Lee Hwi Jae took the twins to see the Lonely Tree at Olympic Park, Seoul. They enjoyed a picnic surrounded by beautiful scenery and the sound of children laughing, and Lee Hwi Jae couldn't have been happier.

That is until Suh Un and Suh Joon started fighting over a monopod or a 'selfie stick' when Lee Hwi Jae took it out for a family snapshot, leaving their father at a loss about what to do.

Find out what happens during this picnic this Sunday!