Sex therapist Ruth Westheimer, better known as Dr. Ruth, rarely turns down an opportunity to speak about sex. In fact, she recently celebrated her 85th birthday by giving a talk, The Art of Arousal, at the Museum of Fine Arts in Houston. And she continues to dispense frank advice as she has since her first radio show, Sexually Speaking, in 1980.

The only difference today is that Dr. Ruth does it on her YouTube channel, Web site and Twitter feed. She has written 39 books, including Sex for Dummies and is at work on a new one. And this month, a play about her life, Becoming Dr. Ruth, began a run in Hartford, Conn.

“That’s pretty neat,” she said.

As a young woman, Dr. Ruth was a kindergarten teacher and pursued a doctorate in education at Columbia University. But a stint at Planned Parenthood piqued her interest in human sexuality. This spring, the organization awarded Dr. Ruth the Margaret Sanger Award, “for her lifelong commitment to empowering women and men to talk openly and honestly about sex and sexual health.”

The essence of her advice, she said, is the importance of relationships and family. Born in Germany, the only child of an Orthodox Jewish couple, she survived the Holocaust after being sent on her own to Switzerland in 1939 when she was 10 years old. She never saw her family again and assumes her parents died in a concentration camp. “Everything else, sexual enrichment, other positions, all can be taught. But first there has to be a relationship,” she said.

Dr. Ruth has been married three times (two divorces, one death) and has two children. She spoke with The Washington Post in a recent telephone interview from her apartment in New York, where she has lived for half a century. Her trademark German accent, wit and frankness, are still intact.

Q. How have you stayed so active?

I love being Dr. Ruth, so I have never thought of retiring. I also took to heart this saying: “Not to retire, but to rewire.” That means “Don’t retire and sit in a rocking chair, but do something else that is of interest to you.”

So in my case for example, something brand new: a book coming out this November. It is called The Myths of Love — m-y-t-h-s.

It’s the Greek and Roman myths, of love with my interpretation, like Leda and the Swan.

Q. So life has been good for you.

I am fortunate. I am fortunate I am living in New York. I am fortunate I can afford car services to Washington Heights, where I have lived for 50 years in the same apartment, overlooking the Hudson. My daughter and family live 10 minutes from my house, and my son in Ottawa, one hour by plane.

My apartment was just decorated by Nate Berkus, the decorator: B-e-r-k-u-s. He used to work with Oprah. He decorated it when he had his television show, then I was on his show, before and after and on page 141 of his coffee-table book. It is called The Things That Matter. It shows how I collect turtles. Turtles, but not live turtles, but all kind of figurines.

Q. Why turtles?

A turtle, if it stays in one place, is safe because it carries its house on its back. Nothing can happen to that turtle.

There is another reason for the turtle. “Turtle” in German is called “scischildkroete.” S-c-i-s-c-h-i-l-d-k-r-o-e-t-e. That is the brand name of the dolls that I used to have in Frankfurt before I had to leave my grandmother — my mother and father were already in a labor camp — so that symbol of a turtle connects me with my past and with my early childhood, which was a happy one.