The pop star poses with her sons.

OK! magazine has the new posed photos of BRITNEY SPEARS with her sons JAYDEN JAMES and SEAN PRESTON. In the issue, which will be on newsstands Thursday, photographer DANI BRUBAKER reveals what the embattled pop star's reaction was to seeing the pictures for the very first time.

"I'm told that when she saw the photographs she literally cried over an hour and stared at them all night long," says Brubaker, who points out that Britney was "very attentive" to the needs of her children during the photo shoot. In fact, the magazine goes on to quote a friend of Britney's, who says "those boys are her everything, and she's said repeatedly that life isn't worth living if she can't have her babies with her."

What's more, the friend reveals that "Britney has always said, 'I would die for my boys if that's what it took to prove I loved them. I'd do anything for them.'"