Britney Spears was between a rock and a hard place in Las Vegas.
The dramatic divorcée showed up at a Sin City night club grand opening party on Friday night sporting a huge diamond rock on her left ring finger – the traditional spot for engagement bands.
“I couldn’t believe what I was seeing,” said one onlooker.
“She marched in with her security guards displaying the stone to everyone – either she’s about to do a Vegas wedding again and get hitched, or she’s just too dim to realize where she put the ring.”
Fueling the rumor mill, the blond-wigged pop tart was later spotted getting up close and personal with magician Criss Angel in the VIP room at LAX club in the Luxor Hotel and Casino.
A source close to Angel – a Long Island native whose estranged wife accused Cameron Diaz of busting up their marriage – said there’s definitely no marriage plans in their future.
“They met to talk about performance stuff and anything Criss could do to lend a hand,” said the source. “That’s the extent of it.”
It wouldn’t be Spears’ first relationship shocker in Sin City.
She married childhood friend Jason Alexander in 2004, but had the marriage annulled before the ink was barely dry on the wedding certificate.
As guest of honor at LAX’s opening, Spears, dressed in a white baby-doll dress and fedora, had been expected to perform.
But despite the hype surrounding her new single “Gimme Gimme,” she remained in the VIP section of the club for the duration of the event.
The crowd saluted the star when she arrived flanked by security.
A reveler said, “She was kind of hard to see because there were a lot of security around her. But when she arrived, the deejay turned down all the music and said, ‘We have a mega-superstar for the grand opening of LAX . . . Britney Spears!’ ”
The crowd went wild cheering for Britney, according to the source.
“After that, they played her new song. She danced a little bit with Criss Angel, who was right next to her. At one point, he kissed her hand, but that was as much as we saw,” said the source.
“She stood up and danced for a little bit when ‘Billie Jean’ was on,” said a mole.
At 2 a.m., the star and her friends left the club flanked by more than 10 security guards. jennifer.fermino@nypost.com