Mary Cheney, who married a woman last year, had some choice words for her sister, Liz Cheney, Sunday after Liz again voiced her opposition to same-sex marriage.

"Liz - this isn't just an issue on which we disagree - you're just wrong - and on the wrong side of history," Mary Cheney posted on Facebook.

Their father, former Vice President Dick Cheney, weighed in on the sisters' disagreement last month in an interview with Jake Tapper:
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