BRITNEY Spears thought telling the world she's engaged to dancer Kevin Federline would be her most romantic moment.

But her romantic dream was shattered with the news Federline only a few weeks ago was engaged to someone else.

An obscure American actor named Shar Jackson, 27, revealed she is eight months pregnant by the 26-year-old, who is also the father of her two-year-old daughter. And she said his engagement to Spears, 22, was the best thing that could have happened to her.

She sarcastically told the couple they were perfectly suited because: "You both smoke, you both drink and you both cheated on significant others. You guys are made for each other. Have a good life."

Federline, who once worked for Spears' first lover, Justin Timberlake, didn't tell her he was engaged.

Friends were alarmed when only three days after they met, and ringed by paparazzi, she frolicked with him on a Los Angeles beach.

There already were fears that Spears' increasingly wild image -- black leather outfits, smoking and rumours of drinking sprees and promiscuous sex -- were alienating her target audience of prepubescent girls who first become fans of her virginal image.

One friend said Spears was out of control even before meeting Federline -- reaching a nadir six months ago with her 55-day Las Vegas marriage to muscle-bound Jason Alexander.

"Federline is not the kind of guy you would expect Britney to hang out with. Once she was careful about who she was seen with, but lately she stopped caring," another friend observed.

Last month she flew Federline from LA to London, saying she felt lonely on tour. They frolicked in the roof-top pool of her five-star hotel and went to a gay and lesbian club.

Spears' penchant for the kind of swaggering, heavy drinker who sees pretty girls as trophies, echoes the relationship her mother, Lynne, had with her father, Jamie.

"If Britney had had a comfort able childhood, maybe she wouldn't have grown up to be the forceful personality that she is today," Jamie bragged recently.

Money worries dogged Spears' childhood, with her parents declaring bankruptcy owing almost $110,000, just six months before her first hit, Baby One More Time.

Jamie said with a bitter laugh: "I squandered it on beer."

Her determination to pay back her parents may have made Spears hungry for success. Whether her childhood is also influencing her choice of men is a moot point.