K. Will and Lee Hyun are known for their close friendship (along with Wheesung), and in Lee Hyun's recent SNS updates, the singer showed off his support and friendship with the star by attending and performing a surprise duet at his concert. On December 26th, Lee Hyun wrote on his Me2day, "I went to K. Will hyung's concert today. Someone had sent a congratulatory stand of flowers that really emotionally connected with me. I took a picture to show you all." As custom for Korean concerts, fans and star friends sent in flowers to wish K. Will a successful concert. One of them was caught by Lee Hyun with the message, "Do you want to sing well? It's not hard. You just have to look like K. Will! Absolutely handsome K. Will!" In addition, he wrote on his Twitter, "I was also randomly called up on stage to perform a duet of "Love 119'. It made me tear up a bit.. It'd be fun to do something like this for my own concert, right?" In related news, Lee Hyun will be releasing his first solo album on January 4th. Source + Photos: OSEN