"Desi Arnaz Jr. loves me, and I love him. We are so close," Sean says. "Science tells me … that he's not my biological father. Science tells me that Mike Tell is."
Sean considers John Astin his father, since he was raised by the actor. But he also maintains relationships with all three men in question, and his step-father, Mike Pearce, who married Duke in 1986.
"I can call any of them on the phone any time I want to," says Sean. "John, Desi, Mike or Papa Mike … my four dads."
His mother prefers to believe that Arnaz is Sean's biological father, in spite of the blood tests. So mother and son have agreed to disagree, and seem closer and more connected than ever.
"I think how we have survived it is that we are people who believe in forgiveness, and moving on," said Duke.
"Well, I don't think there's anything that much to forgive," said Astin. "I mean, not to me."
Duke says she is tremendously proud of her son's acting career. But she's most proud of his real-life character as he overcame a troubled childhood to become a mature adult. "He is at the core the decent, generous, loving, respectful man that I hoped he would be," she said.
She continues to work as an actress, most recently filming a series of mysteries for the Hallmark Channel which premieres Sept. 5.
In the end, the showbiz family is not so different from many others, with fights and forgiveness, illness and health, and ultimately enough love to survive it all.
"What I love the most about my mother is that she's a survivor. She wants to live. She's here. Because she wants to be," said Astin. "That's a good thing."