LATEST: Jessica Simpson has hit back at reports she sacked her best friend and assistant CACEE COBB because she was too close to estranged husband Nick Lachey. After two years, Cobb is moving on from her position as the star's assistant to pursue behind-the-scenes work in the entertainment industry. Simpson's spokesperson explains, "CaCee and Jessica will remain close friends. And CaCee will continue to assist Jess until the end of the month (MAY06)." Cobb has kept in close contact with Lachey throughout the couple's break-up. The pair were photographed chatting all night at a Las Vegas, Nevada club in April (06) and were seen together again on 1 May (06) at a nightclub in Los Angeles. A source tells American publication Us Weekly, "Insiders know she was fired." Another source adds, "Maintaining a friendship with Nick was important to CaCee. She was determined to do it, despite what Jess wanted."