Donald Trump and Marco Rubio exchange shots over who's the sweatier candidate

GOP frontrunner Donald Trump and rival Marco Rubio are now arguing over who is the more awkwardly sweaty candidate.

The two exchanged barbs throughout most of Thursday night's GOP debate - some of the strongest attacks launched between the two during the campaign.

On Friday morning, Rubio said Trump, who often derides the candidate for being sweaty, had "a meltdown" backstage, even insinuating that Trump possibly "wet" himself.

"He called me Mr. Meltdown," Rubio said.

Rubio added:

Let me tell you, during one of the breaks - two of the breaks - he went backstage. He was having a meltdown. First he had this little makeup thing, applying makeup around his mustache, because he had one of those sweat mustaches. Then he asked for a full-length mirror. I don't know why, because the podium goes up to here. Maybe he was making sure his pants weren't wet. I don't know.

Trump fired back later in the day during a press conference in which New Jersey Gov. Chris Christie, a former presidential candidate who has previously railed on Rubio, endorsed the New York real-estate magnate,

"I'll tell you about backstage," Trump said.

Trump continued:

He's with a pile of makeup putting it on his face, I said Marco, easy with the makeup, you don't need that much. You know the story with Marco. I watched Marco with this man [Christie]. Where Marco, he was right over here I asked him I said are you okay? He looked like he just came out of a swimming pool. He was a mess.

Trump said Rubio was putting makeup on with a "trowel."

"He's a nervous Nellie," Trump claimed. "I watched him backstage, he's a mess, the guy's a total mess. I joked recently, could you imagine Putin sitting there waiting for a meeting, and Rubio walks in and he's totally drenched? I don't know what it is but I have never seen a human being sweat like this man sweats."

Trump later thanked Christie for his well-known evisceration of Rubio earlier this month during a New Hampshire Republican debate, in which Rubio responded to Christie's attacks by repeating the same canned line. 

"I thought he was going to die," Trump said.

Trump continued the debate on Twitter Friday afternoon.