Lee Joon made a surprise appearance on "Radio Star."

In MBC "Radio Star" aired today, MC Kyuhyun asked guest Oh Yeon Seo for her ideal type, and she picked her virtual husband from MBC "We Got Married," MBLAQ's Lee Joon.

But right when she said this, Lee Joon came out from the back and hugged Oh Yeon Seo.

Oh Yeon Seo seemed shy, but she could not hide her happiness. The MCs who saw this told Lee Joon, "Oh Yeon Seo was complaining that there hasn't been enough intimacy between you two," and Lee Joon answered, "I was shocked that I hugged her too," bringing laughter to the set.

Photo Credit: MBC