"I love Mary very much. I love her family very much," Liz Cheney said during an appearance on "Fox News Sunday." "This is just an issue on which we disagree."
The remark rankled Mary Cheney, who responded on her Facebook page.
“Liz — this isn’t just an issue on which we disagree you’re just wrong — and on the wrong side of history," Mary Cheney wrote, according to the New York Times.
It wasn't the first time that Mary Cheney has criticized her sister on the subject. But according to the Times, their relationship has soured over the disagreement and they haven't spoken since the summer. Their father, former Vice President Dick Cheney, has said that he has no problem with gay nuptials.
Mary Cheney's wife, Heather Poe, took an even more pointed shot by drawing attention to Liz Cheney's relocation from Virginia to Wyoming for next year's Senate race.
“I can’t help but wonder how Liz would feel if as she moved from state to state, she discovered that her family was protected in one but not the other,” Poe wrote on her Facebook page, as quoted by the Times.