James Marsden is to become a father for the third time

The `X-Men` star is having a baby with Brazilian model Rose Costa, whom he started dating after splitting from his wife Lisa Linde last October.

Rose, 24, is believed to be three months pregnant after spending one night with James during a layover in Miami on her way back to Brazil to renew her visa earlier this year.

The unexpected pregnancy is said to have left Rose`s ex-boyfriend, `The Girlfriend Experience` actor Chris Santos heartbroken.

Rose and Chris had been living in Los Angeles together when she decided to move to New York to pursue her modelling career.

It was there where she started dating James, 38, but Chris came to New York and convinced her to return to Los Angeles.

A source told the New York Post newspaper: "Santos found out and flew to New York to win her back, they spent the holidays together and got a new apartment."

When Rose got back from her visa run, she confessed everything to Chris and immediately moved out of the apartment they were sharing.

The source added: "She confessed everything. She told him they hooked up one night, one time."

However, another source insisted Rose and Chris had split before she got together with James.

Rose is planning on keeping the baby, but it is not known if she is still in a relationship with James.

`30 Rock` star James has two children from his 11-year marriage to Lisa, son Jack Holden, 11, and daughter Mary James, six.

sections: Celebrities