Jason Trawick may have celebrated his birthday on Saturday in Mexico, but not everyone is wishing him well!
One inside source close to Britney tells Eonline.com that "he has completely changed since he first started working with her. And I don't think it's for the better."
The source, who's known Britney for years, says Jason isn't good for Britney. E! says he's "quite the enabler," one reason why Britney keeps him around.
E! concludes with: "we say keep an eye on this guy."