During an appearance on "The Tonight Show Starring Jimmy Fallon" Monday night, the New Jersey governor and presidential candidate told Fallon that he's considering going "nuclear" if he's relegated to the sidelines during the next GOP face-off, which will be moderated by CNN later this month. During the interview, Fallon, who often jokes about Christie during his monologue, pressed the famously brash governor, suggesting that he's been overshadowed by billionaire businessman and Republican front-runner Donald Trump. Christie also talked during the interview about a sleepover he had with rival Marco Rubio at 2012 GOP nominee Mitt Romney's home ahead of a Fourth of July parade in Wolfeboro, New Hampshire. After dinner the night before the parade, he said, Romney invited the two competitors, along with their families and a handful of his grandkids on a boat ride that included an unexpected stop for ice cream.