Lindsay Lohan has hit out at US oil heiress Barbara Davis after she told pals the actress was dating her grandson BRANDON. The matriarch insists Lohan and Davis - whose ex-girlfriends include MISCHA BARTON - are an item, despite Brandon having been caught on video mocking the actress' lifestyle and personal hygiene recently. Barbara - the widow of oil tycoon MARVIN DAVIS - told guests at Kenny G's birthday party in California at the weekend (3JUN06), "Brandon is dating Lindsay now!" A spokesperson later confirmed the story to PageSix.com. But Lohan is furious. He publicist LESLIE SLOANE tells the website, "It is unfortunate that Barbara Davis is desperate enough to make up a lie about Lindsay dating her grandson. "Lindsay took the high road and accepted Brandon's apology last week, but they are not dating and they did not go to dinner together. Lindsay is dating several men who live overseas."