Girls' Generation's Sunny appeared on the radio special of MBC's 'Infinity Challenge' on October 4. 

She visited Jung Hyung Don, who took over as a one-day DJ for MBC FM4U's 'Bae Chul Soo's Music Camp', and saw that Jung Hyung Don messed up by suddenly stopping a CD. He apologized to the listeners, saying, "The CD turned off. I apologize."

Jung Hyung Don saw Sunny and greeted her by complimenting himself. He said, "I'm really good, aren't I?" Sunny responded, "Why do you cut off each word?" He replied, "You don't use the console, right?" The Girls' Generation member then quipped, "Yes, you're right. I don't use it because I might mess up like you."

Watch Sunny's appearance below!