The 45-year-old Family Stone star is currently prepping to step behind the camera for a film tentatively titled Keeping It Together, about a couple's therapist whose own marriage is falling apart.

The script has been circulating since last year, an insider says, and was once a potential vehicle for Grey's Anatomy star Katherine Heigl.

Mulroney finalized his own divorce from actress Catherine Keener just over a year ago, They share a son, nine-year-old Clyde. In March of 2008, Mulroney welcomed a little girl, Mabel Ray, with girlfriend Tharita Catulle.

The star is best known for romantic leads in My Best Friend's Wedding and The Wedding Date.

No cast has yet been confirmed. Reps for Mulroney would not return calls for comment.