The Opposite of Sex

The Opposite of Sex is a 1998 film written and directed by Don Roos and stars Christina Ricci, Martin Donovan and Lisa Kudrow.

Although he is living with Matt Ivan Sergei, Bill still mourns the loss of his previous partner, Tom, who died of AIDS some time ago. Bill maintains a friendship with Toms younger sister, Lucia Lisa Kudrow, who idolized her brother.Dedee seduces Matt, then tricks him into believing he has impregnated her. They elope, leaving Bill and Lucia to track them down. ........

Source: Wikipedia