Singer turned actor Seo In Guk revealed he was once disappointed by his senior Yoon Jong Shin.

On the December 12th broadcast of MBC's 'Radio Star', Seo In Guk began by saying, "I was very disappointed in Yoon Jong Shin when I previously appeared on 'Radio Star'."

He continued, "Yoon Jong Shin sunbae and I have once appeared together on a cable program, so I believed he would take care of me [when I appear on 'Radio Star']. Before we went into recording, he was very affectionate and treated me well, but once the recording began, he would just look down at his script whenever I talked."

"It would've been better if he had just told me that it was getting boring, but instead he ignored me," Seo In Guk said, expressing his sadness and slight disappointment.