BTOB's Ilhoon appeared as a special guest on the January 6 episode of the MBC program 'TMI Under Nineteen', a talk show taking fans behind the scenes of the boy band survival show 'Under Nineteen'.

The episode focused on the trainee hopefuls' hidden talents and special charms. During the episode, contestants Lee Ye Chan and Jeon Do Yeom were determined to outdo Ilhoon with their own performances of the "Gwiyomi Song," a 'cutesy' song with its own special hand gestures that went viral after Ilhoon released a video performing it. Another contestant, Ji Jin Seok, even attempted to give the song an acoustic R&B twist.

While talking with 'TMI Under Nineteen' MC Kim Shin Young, Ilhoon explained that being completely shameless with your "Gwiyomi Song" performance was key. He then performed it himself for Kim Shin Young, despite clearly getting more and more flustered as the song went on.

"Even now, whenever I do it, I have to maintain my shamelessness even thought my ears turn red [from embarrassment]," he laughed, the camera moving to indicate his newly reddened ears.

Check out every version of the "Gwiyomi Song" here!