Wisconsin Gov. Scott Walker’s (R) family disagrees with his hardline stance on same-sex marriage, his wife revealed in an interview with The Washington Post published late Sunday.

Walker called the Supreme Court’s landmark 5-4 ruling legalizing gay marriage across the country last month a “grave mistake” and expressed support for a constitutional amendment allowing individual states to define marriage. He previously supported an amendment to the Wisconsin Constitution that banned same-sex marriage, but seemed resigned to the reality of gay marriage when it began in the state last fall.

Tonette Walker told the Post that the couple’s college-aged sons, Matt and Alex, weren’t happy with their father’s reaction to the Court’s decision.

“That was a hard one,” she said, as quoted by the newspaper. “Our sons were disappointed. . . . I was torn. I have children who are very passionate [in favor of same-sex marriage], and Scott was on his side very passionate.”

She added that her own perspective on same-sex marriage has been colored by her close relationship with a lesbian cousin, whom friends told the Post has vacationed and hosted parties with Wisconsin’s first family.

“It’s hard for me because I have a cousin who I love dearly — she is like a sister to me — who is married to a woman, her partner of 18 years,” Tonette Walker told the newspaper.

The governor told the Post that he doesn’t necessarily change his position on an issue if his family disagrees with him. But he said it may lead to “finding a different way of explaining it, so they can appreciate where I am coming from.”