Cleopatra's Second Husband (2000)

When Robert takes his controlling wife Hallie away for holiday in hopes of conceiving a child, he leaves his other children in the hands of a young couple, Zack and Sophie, who are new to LA. Upon their return home, Hallie decides to move out and soon Sophie joins her. Initially Robert and Zack revel in their newfound bachelorhood, until Robert learns firsthand of Zack's insidiously domineering and manipulative evil side.