Trump tried out his ‘horseface’ insult for weeks in the White House before launching it on Twitter

President Donald Trump had been waiting to hurl his "horseface" insult at Stormy Daniels and even tried it out with White House aides, who advised him not to tweet about his former mistress.

The president reacted to a judge tossing a defamation suit filed against him by Daniels with a Monday morning tweet insulting the adult performer's looks and her attorney Michael Avenatti's legal skills, after workshopping the attacks with associates, reported The Daily Beast.

One White House official and two other sources who speak regularly with the president told the website that Trump had been itching to hit back at Daniels and her attorney for months, but his associates advised him not to elevate the pair.

However, the president was convinced that attacking Daniels with a cruel nickname would fire up his supporters -- just as he believes calling North Korean leader Kim Jong-un "rocket man" had done.

“They love it — love it — when I fight," Trump told associates in recent weeks. "It’s great."

Trump had been slipping the "horseface" insult into private conversations with White House aides, close friends and associates, the website reported.

One source close to the president remembers Trump referring to his former mistress as "that f*cking horseface" in a passing remark.

A course said Trump privately tests out nicknames and insults before dropping them into rally speeches or on Twitter, but didn't describe any that hadn't made the cut.

“(This is) one of the wildest nicknames so far, that’s for sure,” the source said.

Trump was particularly eager to attack Daniels after she described his genitalia in graphic and humiliating detail in a new book, and the former porn actress reminded her social media followers of those claims in a response tweet.