October 15, 2017. According to the QQ Music official website, Joker Xue's "Regret" was released on October 15, 2017, and is included in Joker Xue's 2017 album "The Masked Singer Guess Season 2 Issue 6" . Excerpts from the lyrics: We are familiar with each other's living habits. You are no longer by my side, but I can't forget your face.