Jennifer Aniston seems to have grown tired of her good girl image and is getting to grips with a much moodier one, at least according to sources on the set of her latest movie.

The former Friends star - who recently dumped John Mayer, allegedly for his love of Twitter - is said to be suffering form a severe case of the grumps as she films scenes for The Baster in New York.

“Jen kept mostly to herself," an on-set source tells OK! magazine.

"She didn’t talk to anyone during the breaks.”

And it seems John's pet hate about Jen's vanity has seeped over into her work routine, with cast and crew members reportedly getting very irritated by her long-winded beauty routine.

"In the morning, the cast and crew had to wait to start filming without Jen because she asked for extra time to finishing blow-drying her hair," reveals one source.

We think Jen's gonna have to try a bit harder is she wants to compete with the big bitches of diva-dom!

See Jen in Marley & Me below