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The war of words between Republican presidential rivals Donald Trump and Ted Cruz is growing uglier by the day.

Now their wives, Melania Trump and Heidi Cruz, are being dragged into the mudslinging.

The latest exchange was sparked when an anti-Trump super PAC launched an ad that shows Melania posing nude during a 2000 GQ photo shoot. It suggested that voters should turn out for Cruz or Melania could be the next first lady.

Trump quickly responded with a threat:

Cruz pointed out that the ad came from a super PAC that's not affiliated with his campaign, also calling Trump a "coward" for going after his wife:

Trump, however, wasn't buying it:

The social media battle took another turn Wednesday after Trump retweeted a picture of Melania alongside an unflattering image of Heidi:

Cruz responded, chastising Trump for attacking a woman:

Watch Howard Kurtz react to these "locker room taunts" above.

See Andrea Tantaros' reaction, here.

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