Spears recovered from the bitter custody battle with ex-husband Kevin Federline, by sunbathing with pals on a beach in Mexico.
However, the rumours really started flying after she was seen dancing intimately with a guy.
The two were laughing and joking together as they mock ballroom-danced around the pool, with Spears showing off her newly toned and tanned body.
'Britney looked great in her bikini. She was having a whale of a time with this bloke (man), they seemed close,' Contactmusic quoted an onlooker as telling Britain's Daily Mirror newspaper.
The trip was taken just days after Spears agreed to a custody settlement with Federline.
Federline retains full custody of their young sons Sean Preston and Jayden James, while she will pay him 20,000 dollars-a-month in child support.
Text: ANI | Photograph: Steve Finn