"Lucifer in the flesh," Boehner said of the Texas senator, according to the student newspaper The Stanford Daily. "I have Democrat friends and Republican friends. I get along with almost everyone, but I have never worked with a more miserable son of a bitch in my life."
The former house speaker, whose hatred for Cruz is well known in Washington, also said he would not vote for the junior senator if he were the Republican nominee, but he would vote for Donald Trump. Boehner added that he was "texting buddies" with the billionaire businessman and had played golf with him.
Cruz took to Twitter to fire back at Boehner, saying, "Tell me again who will stand up to Washington? Trump, who's Boehner's 'texting and golfing buddy,' or Carly [Fiorina] & me?"
It's no secret that Cruz is unpopular among his fellow Republicans, and this is not the first time Boehner has voiced his dislike for the presidential hopeful, whom he's previously called a "jackass" and a "false prophet."
In his Stanford talk on Wednesday, Boehner also mocked Democratic front-runner Hillary Clinton, saying, "Oh I'm a woman, vote for me," to a negative reaction from the crowd.
He later added that he thinks the former secretary of state is very accomplished and smart. But if things don't go according to plan for her: "Don't be shocked … if two weeks before the [Democratic] convention, here comes Joe Biden parachuting in and Barack Obama fanning the flames to make it all happen," Boehner said.