When Samantha, a consultant to a California nonprofit corporation, is invited to company events in which spouses are welcome, she brings her housemate, Jill, a college professor. The two women are rarely explicit about their relationship. They just assume that co-workers will infer, correctly, that they are lovers. "I never came out and told people at work I was a lesbian," Samantha says. "You don't come out and tell people you're straight. I felt it was up to them to figure it out."
By the standards of the homosexual world, Samantha and Jill are more than usually open, or "out." Their...