Fox contributor Pastor Robert Jeffress during Friday’s “The O’Reilly Factor” likened gay marriage to incest while arguing that the Supreme Court shouldn’t make gay marriage a civil right.

“If you expand the definition of marriage to two men and two women, why stop there?” Jeffress said. “If it’s an absolute constitutional right, why can’t 16-year-olds get married? Why can’t polygamists get married? Why can’t siblings get married? Where do you stop? It opens up a Pandora’s box of societal-wide chaos.”

Jeffress, who signed a brief asking the Supreme Court to uphold state bans on same-sex marriage, also agreed with host Bill O’Reilly’s comments that Christians were under attack in America.

“I believe that if the Supreme Court, as expected, enshrines gay marriage as a constitutional right, I believe it’s truly going to be, to use your phrase, ‘open season’ on Christians and those who believe in traditional marriage,” Jeffress said. “Once you make gay marriage a civil right then anyone who opposes it is guilty of a civil rights violation.”

Watch the video below, courtesy of Media Matters: