Are Sienna Miller & Balthazar Getty on the rocks already?

Sienna Miller is reportedly afraid that her relationship with Balthazar Getty that is on the rocks. Friends of the actress say she fears that her relationship is “as good as over” because Balthazar has refused to file for divorce from his wife, Rosetta Millington.

Sources say that the couple have had their fights over how much time she spends socializing. While she’s partying, he prefers a much quieter life.

Friends have said that she was hoping to set up home with Balthazar permanently, but flew home to London last week, after their fights, saying that she wanted a “cooling off” period.

Source close to Sienna say that she’s afraid he’ll go back to his wife and children.

A source said, “Sienna is back in London to give them both some cooling-off time. They are still together at the moment but she has said things aren’t good. There have been some pretty unpleasant rows, largely over Balthazar’s reluctance to commit. She has really wanted to be able to step out as a couple but Balthazar is very torn over his children and it looks like he might be wanting to go back to his family. Sienna is devastated.”

We’ll see what happens on this one, but if Rosetta is keeping him from his children, it might be reason enough for him to go back to her.