"You look like you were having a blast," Fallon said sarcastically. "Were you being held hostage at this time?"
Christie responded: "This is what you would look like if you were standing behind Jay Leno when he was doing his monologue."
The crowd groaned, perhaps not knowing what Christie meant.
"If you're used to talking, it's awkward not to talk," Christie said. "So if you're standing there, I'm listening."
Fallon suggested Christie should have moved so he wasn't directly over Trump's shoulder. Fallon then pulled out a cardboard cut-out of Christie and put it behind Christie's shoulder, and asked him, "Do you find that distracting?"
"No," Christie insisted. "He looks serious. He's listening."
Things didn't get much better from there. Fallon asked Christie why he endorsed Trump, and Christie seemed to take exception to the question.
"Because I think he's better than them," Christie said. "It's not that hard. That's why you do it. It wasn't like I drew it out of a hat or something, Jimmy."
Christie then tried to joke that he would have supported Fallon if Fallon had run for president, but the crowd was silent.