The battle between Donald Trump and Ted Cruz is getting personal, with the Texas senator coming out swinging after the Republican front-runner threatened to "spill the beans" on his wife, Heidi, on Tuesday night.
"Most of the things that Donald Trump says have no basis in reality, so we are not worried," Heidi Cruz told reporters on Wednesday morning, when asked about the threat.
Just as the two candidates were notching big primary wins, the feud got unexpectedly heated when Trump blamed the Texas senator for an ad his campaign did not create and, in response, threatened to reveal damaging details about Cruz's wife. While the candidates spent months playing nice early in the election cycle, their sparring has intensified as the race has whittled down — increasingly, both talk like it's a two man race.
But the Republican front-runner shows no sign of relenting, doubling down in a tweet on Wednesday morning in which he continues to blame Cruz for the ad.
The ad was created by the anti-Trump super PAC Make America Awesome Again: It features a handcuffed-and-naked photo shoot of Melania Trump from 2000, with the caption "meet Melania Trump. Your next first lady. Or, you could support Ted Cruz on Tuesday."
It was a small-dollar ad campaign online, targeting Mormon women in hopes of getting out the vote for Cruz in a state where winning more than 50 percent of the vote was key to the senator's hopes of garnering all of the state's 40 delegates. But the ad exploded online on Tuesday night as polls were closing, when Trump started blaming Cruz.
On Wednesday, in an interview with NBC News' TODAY, Cruz said that threat "speaks volumes about character" and "is the epitome of classlessness."
"If Donald is trying to mess with my wife, he's way out of his league," he continued.
But that's not stopping the Trump team. The presidential candidate's son Eric Trump also blamed the ad on Cruz in an interview on Fox News.
"His super PAC, it's him. It's the same thing, right? I think it's disgusting to tell you the truth, just to be completely honest. Here's a man who praises, who's always talking about morality, 'I'm going to take the high road. I'm going to do this,' and he does that," Eric Trump said.
Mair said she has no ties to Cruz, other than supporting his Senate bid in 2010, and knowing some of his past and present supporters. She believes Trump is blaming Cruz for it in order to attack his wife, and said it's surprising so many are up in arms about an image that's widely available.
Mair said when conceiving of the ad, she recalled the 2000 photoshoot for the British edition of GQ and ran a Google search.
"The first image that came up was this," she said.
This article originally appeared on MSNBC.com.