YoonA was a guest on the December 5 installment of KBS 2TV's 'Happy Together 3' and mentioned that she recently had a phone conversation with her first love.

SEE ALSO: "Almost too late to have children," Discussion sparks over Girls' Generation Members staying Unmarried as they approach their Late 30s

She explained that she had been friends with him back in elementary school, which was about eleven years ago.  She would have felt a bit uncomfortable if he had kept going on about her being in Girls' Generation, but he rather casually said, "To think that the YoonA I knew has come this far!"

She continued, "Worried that he might mention it first, I said, 'I used to like you in the past!'" and the MCs laughed, saying she was trying to put on a tough appearance.

YoonA explained that he had already known about her feelings, but jokingly added he was probably filled with regret now.