Horseplay is a 2014 Hong Kong action comedy film directed by Lee Chi-ngai and starring Tony Leung, Ekin Cheng and Kelly Chen. The film's Cantonese and Mandarin theme song, Why Not Tonight (不如今晚) and The Best Night (最好的夜晚) respectively, was adapted from Henry Mancini's It Had Better Be Tonight with Leung, Cheng and Chen performing. Leung and Chen performed the Mandarin version at the 2014 CCTV Lunar New Year Evening on 30 January 2014.
While interviewing for a relics smuggling case in London, television hostess Ha Mui (Kelly Chen) meets multi-faced thief Nine-Tailed Fox (Tony Leung) and washed out police detective Cheung Ho (Ekin Cheng). One wants to reveal the truth, one wants to steal the "Tang Dynasty Pottery Horse" and one wants to bring criminals to justice. The three of them have different goals, but they must work together to acquire the pottery, which also results in the hunt for Nine-Tailed Fox by his rivals. What will be the final outcome?