Scarllett Johansson & Sean Penn on the rocks?

Scarllett Johansson’s romance with Sean Penn is already on the rocks according to a new report.

American tabloid the National Enquirer claims the pair have started to fight because Sean, 50, has been acting like a control freak on the set of Scarlett’s latest movie We Bought a Zoo.

“Sean’s been coming to the set daily and watching Scarlett’s every move,” an insider said.

“He scowls at any guy who talks to Scarlett or even looks at her unless it’s work-related, and he demands that people bend over backward to accommodate her.

“If Scarlett’s hungry, Sean orders a set assistant to get exactly what she wants from a local restaurant. If he notices a smudge on her skin or a problem with her wardrobe, he orders the makeup and costume people to fix it.

“It’s bizarre that he’s involved in such tiny details.

“Scarlett is a free spirit, and she was attracted to Sean for his bad boy reputation.

“She thought he’d be a fun rebound after her failed marriage, and she respects him as an actor and activist. But she wants superstar Sean, not someone who acts like her dad.”

Johansson and Ryan Reynolds, 34, split in December after two years of marriage. In August of 2009, Robin Wright, 44, filed for divorce from Penn. The couple had been married 13 years.

Scarlett and Sean were first linked last month.

“Scarlett first reached to Sean when she was planning to visit Haiti with Oxfam,” a source told Us Weekly magazine.

“She knew Sean was living there in a tent and turned to him for advice.

“Scarlett’s smitten with him.”