Britney Spears has turned to ex-lover Justin Timberlake to cope with the breakdown of her second marriage.It has been claimed that Britney was making tearful phone calls to Justin even before she filed for divorce from Kevin Federline last week.A source told Britain's Grazia magazine: "Justin said Britney has called him crying a number of times about her relationship with Kevin. She has gone through an excruciating time. It's very sad. She doesn't want anybody to feel sorry for her or see her as a victim. She has been trying for months to make it work for the sake of her children."One of the tracks on Justin's new album 'FutureSex/LoveSounds' appears to be a warning to an ex-girlfriend, strongly believed to be Britney, about staying with an unfaithful partner.The lyrics to 'What Goes Around...Comes Around' read: "You spend your nights alone/ And he never comes home/ And every time you call him/ All you get is a busy tone/ I heard you found out/ That he's doing to you/ What you did to me."Britney filed for divorce last week after allegedly catching Kevin with another woman in a New York hotel.