Seo In Guk showed his close friendship with fellow contestants from the 'Superstar K' series.

On April 13th, Seo In Guk tweeted, "In Music Bank's waiting room with people who I don't get to see often, but are like family [to me].�Huh Gak hyung and John Park."

The three 'Superstar K' brothers all put up matching peace signs for the camera. Fans especially noticed Seo In Guk's new, sharper jaw line as he reportedly lost 22 pounds (10kg) for his recent comeback.

Followers commented, "Seo In Guk's face is really small", "Where's Busker Busker?", and "Superstar K artists have taken over the music scene".

Source & Picture: Seo In Guk's�Twitter