Marifil Niña Girado-Enriquez, known professionally as Nina, is a Filipino singer and record producer. She made her recording debut in 2002 after signing a recording contract with Warner Music Philippines. Her first two studio albums produced the chart-topping singles "Jealous", "Foolish Heart" and "Make You Mine", and earned her the Favorite New Artist award on both Awit Awards and MTV Pilipinas Music Awards. She established her position in the local music industry in 2005 after releasing her third album Nina Live! which was certified diamond by the Philippine Association of the Record Industry (PARI). The album yielded her most successful single, "Love Moves in Mysterious Ways", and her biggest solo concert to date.

"Jealous" is a song by Filipino singer Nina from her 2002 debut studio album Heaven. It was released as the album's second commercial single in February 2003 by Warner Music Philippines. The song was written by international songwriters Shelly Peiken and Brett Laurence, and it was produced by Ferdie Marquez. The song tells a story of a girl who is in love with her ex-boyfriend that has a new girlfriend. She narrates how jealous she is with the girl, and how lucky the girl is. She also promises to wait for the boy, the moment the girl leaves him.