Scarlett Johansson dating Sean Penn?

Scarlett Johansson has apparently started dating Sean Penn.

According to reports, the 26-year-old star is "smitten" with the 50-year-old actor after they got close in January while she was staying at the Chateau Marmont hotel in LA.

A source has spoken out: "Their first hook-up was in Scarlett's bungalow. She is smitten with him."

Johansson and Penn allegedly become friends when she was planned to fly out to Haiti to help those affected by the two earthquakes in January 2010.

An insider added: "Scarlett first reached out to Sean when she was planning to visit Haiti with Oxfam. She knew Sean was living there in a tent and turned to him for advice."

Johansson later did not attend the tip, but the pair have apparently developed feelings for one another.