Singer Belinda Carlisle says she backs gay marriage because her son is gay.

In a newly released interview with gay glossy The Advocate, Carlisle says she supports the institution because she wants what's best for her son James Duke.

“My son is gay, and I want the best for him,” Carlisle, 51, said in explaining why she starred in a public service announcement last year for marriage equality.

“I don't understand why gay marriage is such a divisive issue in the first place,” she added.

Carlisle explained that she recorded the video in her backyard after her son got her riled up on the issue.

“I've been always been really opinionated, and I think at this point in my life I don't have a lot to lose by saying what I feel.”

Carlisle, who first gained fame as a member of the all-girl band the Go-Go's, also said her son's announcement at 15 that he's gay took her and her husband by surprise.

“The first thing I thought about was how difficult it could be for him,” she said. “It was a big, intense process. It took six months to a year for the dynamics in our family to adjust, but I wouldn't want him any other way, honestly.”

Carlisle will release her 272-page memoir Lips Unsealed by publisher Crown on Monday.