Piers Morgan Piers Morgan

Delaware Tea Party candidate Christine O'Donnell walked off Piers Morgan Tonight in the middle of her interview Wednesday, becoming Morgan's first walkout in his 25-year career.

Things first turned sour when Morgan asked O'Donnell about her opinion on gay marriage. O'Donnell, who was on the show to promote her new book Troublemaker: Let's Do What It Takes to Make America Great Again, argued that the topic was irrelevant since there is no new legislation and told the host he was "being a little bit rude." Morgan, however,  pointed out he was merely staying on topic since O'Donnell discusses her religious beliefs in the book, but she instead pressed him to ask those who are running for office what they think.

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Morgan then asked O'Donnell why she was being "weird" about the topic. "I'm not being weird about this, Piers. I'm not running for office. I'm not promoting a legislative agenda. I'm promoting the policies that I lay out in the book," she said. "That's why I agreed to come on your show. ... Don't you think as a host, if I say this is what I want to talk about, that's what we should address?"

Morgan politely disagreed with her, before O'Donnell suddenly said she was being pulled away. "We turned down another interview for this," she said. "I was supposed to be speaking at the Republican Women's Club at 6 o'clock and I chose to be a little late for that. ... Not to endure rude talk show hosts, but to talk to you about my book."

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O'Donnell then asked if Morgan had even read Troublemaker before she exited the studio. Morgan took to Twitter soon afterward about the incident, asking viewers to decide whether he was in the right. "My first ever walkout in 25 years of interviews," he tweeted. "I guess viewers can decide if I was 'rude' or not tonight."

Morgan also appeared on Anderson Cooper's CNN show less than an hour before the O'Donnell interview aired to talk about the "strange moment." The host defended himself, saying he thought was he was "a little bit cheeky maybe," but not rude to O'Donnell and that, judging from her reaction the topic, "it looks like she has something to hide."

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Piers Morgan Tonight airs at 9/8c on CNN.

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