Here’s a look back at some of the insults, attacks and slights Christie has thrown Trump’s way -- and vice versa:
The Time He Questioned Trump's Ability to Handle a Crisis
“A crisis for Donald is when his favorite restaurant on the Upper East Side isn’t open,” Christie quipped, after answering a question about how Trump would deal with an economic crisis as president.
The Time He Welcomed Trump Back to the Debate Stage
"Our friend Donald is coming back, we really can't wait to welcome him unless someone insults him between now and Saturday, maybe he won't show up, I don't know," Christie joked during a stop in New Hampshire.
The Time He Couldn't Imagine Trump as President
During a campaign stop in Iowa, a man told the New Jersey governor he couldn’t imagine Trump as president, and Christie responded by saying: “You’re feeling my pain right now.”
He continued: "If you think somehow this is just an act, this is like 'The Apprentice,' I'm telling you, what you see is what you get."
The Time He Disagreed With Trump's Proposal to Ban Muslims From Entering the U.S.
“When Donald Trump said that [proposed ban on Muslims] he was dead wrong,” Christie said during a town hall in Meredith, New Hampshire. “We need to stop the Muslim Jihadist, and we can stop them through appropriate law enforcement and intelligence work, and stop them but not stop every person because, believe me, we need the Muslim Americans in this country to help us catch those people.”
Back in December, Trump called for a "total and complete shutdown" of Muslims entering the U.S. until "our country's representatives can figure out what is going on."
The Time He Refuted Trump's Claim That Thousands Cheered After 9/11
“It didn’t happen, and the fact is, people can say anything, but the facts are the facts, and that didn’t happen in New Jersey that day and hasn’t happened since,” Christie told reporters at a campaign stop in Portsmouth, New Hampshire.
In November, Trump said he saw thousands of people in Jersey City, New Jersey, cheering when the World Trade Center was destroyed on Sept. 11, 2001.
The Time He Said Trump Would 'Take Himself Down'
“Donald will take himself down over time, with some of the stuff that he says. And we all see that. You know. If he really does think he can shoot someone on Fifth Avenue and still keep voters, I think that’s a little bit too much for most voters in the United States.”
Trump joked that he could "shoot somebody" in New York City but still not lose what he called his loyal supporters.
And the New York real estate mogul is guilty of attacking his now-supporter as well:
The Time Christie Had 'No Chance'
“Chris Christie is a friend of mine, he has no chance. Zero,” Trump said when discussing Christie being allowed on the debate stage during a campaign stop in New Hampshire.
The Time Christie Was a 'Little Boy'
In 2012, New Jersey was hit by Superstorm Sandy, the deadliest and most destructive hurricane of the season. After the state was hit, Gov. Christie joined President Barack Obama aboard a Marine One helicopter and surveyed the damage to the Garden State.
Trump called Christie out for ‘mentally’ hugging the president.
“It was like a little boy, 'Oh, I am with the president.' Remember he flew in the helicopter and he was all excited to be in the helicopter. I said, 'I would have put you in my helicopter, it’s much nicer.'”