The Super Bowl is trying to get together celebrities for an all-star NFL Network promo to air during the game, but a source says Britney Spears’ people “were turned down flat out when they asked about participating.”

“She’s too much of a train wreck,” says the insider. “Besides, we already have Paris Hilton. Janet Reno and David Beckham are also on the wish list,” says the source. “Larry David said he might do it. Also, we’re trying to get Predator, from the movie.”

Britney Spears’s friends believe that the baby-popping singer may be pregnant again, according to In Touch Weekly.

The friends’ concern may help to explain why Spears seems not to have lost any of her pregnancy weight and why she has been getting sick lately. In one widely circulated photo, Spears was shown throwing up peanut butter and reports said she had been drinking, but according to ITW, Spears has been skipping the booze. “Her dancers were indulging in Malibu rum and pineapple drinks and taking shots of vodka,” a witness to a January 14 party at a Las Vegas casino told the mag. “But Britney drank bottled water.” Spears gave birth to her second child only four months ago — but friends point out that she got pregnant for the second time only three months after having her first child.

“I’ve seen her during the last two pregnancies and she has the same look now,” a pal who sees Britney every week told the mag. “She’s heavier, but that’s not it. It’s the sparkle in her eye. She always gets that sparkle when she’s pregnant, like she’s relaxed and happy.”

Spears’s rep didn’t return the Scoop’s calls for comment.