R&B star Usher has been slapped with a lawsuit by a former nanny who is suing the singer for wrongful termination. Cecilia Duncan claims that the Yeah! hitmaker hired her as a part-time nanny in December, 2010, but that she regularly worked much longer hours to care for the star's two sons, Usher Raymond V, five, and Naviyd Ely, four, often exceeding 40 hours a week. According to legal papers, obtained by editors at TMZ.com, Duncan alleges she did not receive overtime payment and that she expressed her concerns to the singer in 2011. She claims that her complaints were ignored and she was fired in September last year (12) with the alleged overtime still owed. Duncan is suing Usher for wrongful termination and failure to pay wages.