SAN FRANCISCO (AP) – The son of California’s most prominent opponent of marriage for gays and lesbians exchanged vows with his longtime boyfriend, joining the thousands of same-sex couples who have flocked to City Hall to participate in a rite his father is trying to block in court.

David J. Knight, 42, the son of state Sen. William J. “Pete” Knight, married his partner of 10 years, Joseph A. Lazzaro Jr., 39, during a brief ceremony presided over by a volunteer marriage commissioner. The couple, who live in Baltimore, were accompanied by a friend, but no family members.

The elder Knight is a Republican senator from Palmdale, Calif., who authored a successful 2000 ballot initiative that strengthened California’s ban on marriage for gays and lesbians. Proposition 22, also known as the Knight Initiative, states that only marriages between a man and a woman are recognized as valid in California.

More recently, a nonprofit group the senator leads, the Proposition 22 Legal Defense and Education Fund, has spearheaded one of the ongoing lawsuits seeking to block San Francisco authorities from issuing marriage licenses to gays and lesbians.

In a statement released by his Sacramento office, Senator Knight reiterated his view that the marriages that have been performed during the last three weeks are “illegal and unethical,” but said he had no comment about his son’s actions.

“I love my son, but we continue to disagree on this issue and because this is a personal family matter I do not wish to respond,” he said.

During the Proposition 22 campaign, David Knight, a professional cabinet maker who served as an Air Force fight pilot during the first Persian Gulf War, wrote an opinion piece for the Los Angeles Times entitled “My Father is Wrong on Gays.”

In it, the younger Knight said that his father rejected him upon learning he was gay in 1997 and that the two had remained estranged.

“I believe, based on my experience, that his is a blind, uncaring, uninformed, knee-jerk reaction to a subject about which he knows nothing and wants to know nothing, but which serves his political career,” he said.

Donald Bird, the deputy marriage commissioner who officiated at the Knight-Lazzaro wedding, said he didn’t know until after the ceremony that the two grooms wearing suits and matching rose boutonnieres had an exceptional connection to the ongoing debate over marriage rights for gay and lesbian couples.

“I thanked them for being here to honor our love,” said Bird, who married his male partner of 37 years on Valentine’s Day.