Britney's having marathon sex sessions

Britney Spears' most recent ex beau, model Isaac Cohen has revealed that the singer is close to breaking point, and that the only time she is not in torment, is when she is indulging in marathon sex sessions.

Cohen, who started dating Britney soon after she split from hubby Kevin Federline following a two-year marriage, revealed that the singer was still 'not over' the split when he met her.

"It was clear she was not over her marriage. The first time she invited me to her home I saw her wedding dress hung on the wall in a glass box. As we made love that night it was like Kevin was in bed beside us. She had not even begun to move on with her life," the News of the World quoted him, as saying.

The model also revealed that Spears was most at peace when she was having sex, but once that was over, she would become the 'little girl lost'.

"She loves sex and is incredibly adventurous. She was totally happy when we were locked in each other's arms. But once the sex stopped Britney was like a little girl lost, unable to cope.

"She would lie like a limp rag doll in my arms and and say, 'Why can't everyone leave me alone?' and, 'What have I done to deserve this?'" Cohen revealed.

According to Cohen, the mum-of-two is also constantly racked with insecurities where her figure is concerned.

"Like any woman who has had two children she worried about her figure. As far as I was concerned she was gorgeous, but she had such low self esteem she sometimes would not listen.

"She would say, 'Am I fat? Am I fat?' then spend hours dancing around the house trying to burn off calories. She was always jumping around," he said.

And, Britney's fragile emotional side also came to the fore when she was often so depressed that she would not bother about the way she looked.

"Other times, she got so low she didn't care what she looked like. She could not care less some days if she went out of the house without brushing her hair or checking to see if her outfit matched.

"That's just where she was in her life. She had so much on her plate with the children she had precious little time to worry about how she looked," he said.

And though the singer has been slammed as being an unfit mother, Cohen insists that there is no two people Britney loves more in the world than her sons – Sean Preston and Jayden James.

"Her boys mean everything to her and she worried she might lose them in a custody battle," he said.

Cohen and Spears split earlier this year following a six-week relationship.