Britney Spears has been left feeling like she "can’t trust anyone", a source has told OK! , after the 41-year-old singer found herself at the centre of bombshell drug allegations last week. According to allegations made by journalist Daphne Barak, Britney’s ex-husband Kevin Federline – who was married to the Toxic singer between 2004 and 2007 – had expressed concern over the singer’s substance abuse and vulnerable state, claiming that their sons Preston, 17, and Jayden, 16, had witnessed worrying drug-related activity at her Los Angeles home. Kevin, 45, was quick to deny Barak’s allegations, calling the story "lies" and "repulsive".