"Are they small hands? And he referred to my hands - if they're small something else must be small. I guarantee you there's no problem, I guarantee you."

It didn't take long for Thursday's Republican presidential debate to go below the belt.

Just 10 minutes in, Donald Trump – the grand duke of lofty declarations – cranked his shock factor up a notch to announced the size of his penis to America, Mashable reported.

After Marco Rubio assured Trump that he would refrain from descending into gutter attacks, the Republican frontrunner responded by pointing out a recent Rubio statement in which he said Trump has small hands, apparently implying Trump might be poorly endowed elsewhere.

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— Zeke Miller (@ZekeJMiller) March 4, 2016

"He hit my hands. Nobody has ever hit my hands. Are they small hands? And he referred to my hands – if they're small something else must be small. I guarantee you there's no problem, I guarantee you," Trump said, promising he's got a big enough penis to be the leader of the free world.

And just like that Twitter exploded with penis jokes.