In June 2012, Leeteuk reunited with his Super Junior band-mates for their sixth studio album, "Sexy, Free & Single" released on July 4, 2012. On June 23, Leeteuk's teaser photo was released showing him with platinum silver hair, a gold necklace and heavy black eye makeup. On June 25, he also tweeted another version of his teaser photo with the same outfit but in a different pose, leaning on his hand looking as though he was deep in contemplation. In the repackaged edition of the album, re-titled "Spy", Leeteuk composed "Only U" and co-wrote the lyrics with Donghae.