Yes, The family outing family members Lee Hyori and Daesung performed in Sketchbook!
They performed their duet "How did we get" which is a song from Lee Hyori's 4th album. They also had some more fun and performed other songs!
Lee Hyori and Daesung are for me one of the best celebrity friends there is, cause they are still friends off screen and they just make me laugh!
Check out their once in a lifetime performance! Literally, you would never know when they will perform this song again!
credits: UnknownCarrot110 @ youtube