The New Jersey governor's facial expressions during the Super Tuesday speech have been widely dissected online, becoming a meme.
"All these, like, armchair psychiatrists should give it a break," he said to reporters during a press conference in Trenton, N.J., when asked about his endorsement of Trump.
"He gave a press conference!" Christie said. "It wasn't the kind of circumstance where I would be jumping up and down cheering and smiling."
Christie, a former White House contender who has caught flak from Republicans for endorsing Trump, decried the "hysteria" of those trying to read into any facial cues standing behind Trump.
The moment inspired the hashtags #FreeChrisChristie and #ChristieFace.
"So no, I wasn't being held hostage, no I wasn't sitting up there thinking, 'Oh my god, what have I done?'" he told reporters on Thursday.
"I understand everybody had a lot of fun with it. It doesn't matter to me. I've had a lot of fun on the Internet with people at times too. It's fine."