ABC News' Emily Friedman ( @EmilyABC) reports: In an interview with CNN's Piers Morgan, the second part of which aired tonight on the network, presidential candidate Mitt Romney pushed back against the host's questions about how his Mormon faith might influence his policy should he win the White House in 2012. Asked whether it's actually possible to separate his faith from his job as president should he be elected, Romney responded, "Absolutely. You don't begin to apply doctrines of a religion to responsible of guiding a nation or guiding a state." Romney explained that he is pro-life and that he is in favor of gay rights but believes that marriage should be a union between a man and a woman. Morgan pressed him on what the Mormon church says about gay rights, asking, "What is the Mormon position on homosexuality being a sin?" "I'm not a spokesman for my church," Romney responded. "But don't you know?" Morgan interrupted. "I'm not a spokesman for my church. And one thing I'm not going to do in running for president is become a spokesman for my church or apply a religious test that is simply forbidden by the constitution, I'm not going there," Romney said. "If you want to learn about my church, talk to my church." Unrelenting, Morgan went on asking Romney, "Well, do you personally think homosexuality is a sin?" "Nice try, but I'm not going to get into that," Romney said. "I'm not here in a religious context, I'm here as a candidate for president, and as a candidate for president or as a president I have to represent the interests of all the people," he said. Romney's wife Ann joined him for the later part of the interview, during which Morgan joked that at least the couple's Mormon faith eliminates the risk of scandal during their quest for the White House. Romney says he has only tried alcohol once and has never used drugs. He also has never had an extramarital affair, he told Morgan. "This is one of your trump cards, the one thing we don't have to worry about is something tumbling out of the cupboard," said Morgan, alluding to the most recent political scandal involving Rep. Anthony Weiner, D-N.Y. "Better not," replied Ann Romney, laughing.