When Ms. Locke, who lived in Silver Lake, Calif., about 20 miles away from Ms. Baxter, asked if she could leave a few clothes at Ms. Baxter’s, Ms. Baxter balked. “I said, ‘I don’t have any room,’ and I live in a five-bedroom house,” Ms. Baxter said now, with a fair measure of chagrin. And when she worried that photographers were lurking around her house, she asked Ms. Locke to park her truck down the street. “She just looked at me like ‘Are you smoking crack?’ and had the integrity to say, ‘No,’ ” Ms. Baxter said. “Thinking back, it must have been hugely punishing.”

It was. “One night I’d be her girlfriend and a couple nights later I’d be her friend,” Ms. Locke said. “She’d be warm and tender one minute and the next she’d be like: ‘O.K., see you later.’ I didn’t know where my place was. I’d been out since I was 21 and I didn’t want to live my life that way.”

A year after they started dating, the couple broke up. “I didn’t need to be in a relationship with somebody who didn’t know what she wanted,” Ms. Locke said. “That was not O.K. with me. I started getting weary of it.” And, not willing to give up totally on the relationship and this being Hollywood, the couple went to a therapist. Ms. Locke said she wanted the kind of relationship that changes you spiritually. Ms. Baxter said she wanted the kind of relationship where you have fun and go to movies. Oddly, this quelled the turbulence in the relationship. Ms. Baxter realized she meant just the opposite. “Somehow I understood that there was more here than I was allowing myself to see or want,” she said. “I dropped that wall. I felt like I was a different person.”

“Almost instantly our relationship became a real relationship, and she became dedicated to it,” Ms. Locke said. “No more push and pull. It was: Oh, this is where I’m going to be.”

In 2007, Ms. Locke moved into Ms. Baxter’s five-bedroom house and brought all her clothes. But it wasn’t an easy decision. “I wanted to make sure Nancy Locke got to stay Nancy Locke and for some reason I thought that might disappear if I moved in with her,” she said. “I liked being independent and I thought that might go away.”