Before they were bitter political rivals, Hillary Clinton and Donald Trump were friendly with each other; Clinton and her husband, former president Bill Clinton, even attended Trump’s 2005 wedding. But in a new clip from the upcoming documentary Trumped: Inside the Greatest Political Upset of All Time, the current president explains that he found the Clinton-Trump dynamic a bit more transactional than anything else.

Describing their interaction at Trump’s nuptials as “friendly, a little bit friendly,” Trump says in the new clip (seen below) that his connection to the Clintons was fueled by business.

“They were nice, I was nice. But it’s business. You know the old story: it’s not personal, it’s business,” Trump says to reporters Mark Halperin and John Heilemann during a taped conversation from March of last year. Told that his “old story” originated with the mafia, Trump adds, “That’s all right. It happens to be true.”

Trump’s comment was initially made famous by The Godfather. In Francis Ford Coppola’s film, lead character Michael Corelone (Al Pacino) tells his brother Sonny (James Caan) that retribution against the men who tried to take their father’s life is “not personal, it’s strictly business.” Watch the iconic sequence below.

The clip from Trumped also includes Trump’s thoughts on running against Clinton in the general election (which he would win later in the year).

“The last person she wants to run against is me, and I know that from her people and I know that for a fact,” Trump says. Asked how come Clinton’s people are talking to Trump, the president replies, “They tell me everything.”