Desi Arnaz successfully made a commendable choice before his tragic death.

Arnaz and his wife, Lucille Ball, went through ups and downs throughout their married life. Their daughter, 70-year-old Lucie Arnaz, recently dropped more details about her famous parents' relationship and how her patriarch made them proud and emotional before his passing.

For this week's issue of PEOPLE, Lucie said her father got sober - thanks to her younger brother, Desi Arnaz Jr.

"He resisted going into AA or any program for a long, long time. We don't air our dirty laundry in front of other people; he hated that part. But he finally did after his wife Edy died. He was just so upset that my brother convinced him, I think, 'Come on, Dad. You can do this.' And he did it. He stopped drinking," she said.

Lucie recalled how her father once stood up when he was next to her and said, "My name is Desi, and I'm an alcoholic." For the daughter, it was the proudest moment in her life since she saw her father overcome the hardest thing he had to do.

According to Lucie, getting sober for her father was really hard. But Arnaz, in the end, showed an incredible amount of courage and surpassed the big hurdle.

The Death of Desi Arnaz

Lucie's statements came years after Arnaz passed away on Dec. 2, 1986, due to lung cancer. According to ABC 7 New York, Arnaz died in his daughter Lucie's arms, and it prompted her to ask people not to smoke.

Arnaz and his family found out about the dreaded disease shortly after getting sober.

Meanwhile, Lucie called her parents' marriage something bittersweet. Ball and Arnaz ended their marital relationship in 1960, but the duo reportedly had unconditional love for each other that never went away.

"There was forgiveness. There was understanding. There was an appreciation for that other person and what you got from that other person, regardless of the stuff that hurt that never went away. And that was beautiful and that, in and of itself, was a wonderful thing to leave us," she went on.

Lucie will be part of the new documentary "Lucy and Desi." It will premiere on March 4 on Amazon Prime Video.