Hours after Sen. Rob Portman, the Ohio Republican, bucked his party and came out in support of gay marriage, House Speaker John Boehner, R-Ohio, reaffirmed his position against it in a wide-ranging, exclusive interview with ABC News' Martha Raddatz for "This Week," that will air on Sunday.

Boehner told Raddatz that he could not envision a situation where his views would shift on same-sex marriage - even if one of his children came out as gay.

ABC

"Rob's a great friend and a long-time ally. And I appreciate that he's decided to change his views on this," Boehner said. "I believe that marriage is the union of one man and one woman. … It's what I grew up with. It's what I believe. It's what my church teaches me. And I can't imagine that position would ever change."

Portman, who Mitt Romney considered tapping as a running mate in last year's presidential election, changed his position on same-sex marriage after his son came out to him as gay. The Ohio senator is among a small, but growing number of prominent members of the GOP to express support for gay marriage.

Related: Republican Rob Portman Endorses Same Sex Marriage

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