Las Vegas - Britney Spears‘ romance with David Lucadohas turned toxic! Sources say that although Lucado seems to dote on Spears in public, he disrespects the singer behind her back.“David makes fun of Britney all the time,” a source said. “He says she’s extremely boring and always crack jokes at her expense. “Britney is head-over heels for David, but he’s just using her for the high life.”Recent reports claimed Spears’ family is worried that “she could have another meltdown”. Insiders say the singer is struggling with her residency at Planet Hollywood Las Vegas, and wants to retire.“She isn’t the driven girl that she used to be. Her favorite thing to do is hang out with her kids,” a source explains of her sons Sean, 8, and Jayden, 7. “It wouldn’t surprise me if she retires as soon as her Vegas stint is over.”This news was published in The Nation newspaper. Read complete newspaper of 12-Apr-2014 here.