Joe Biden fiercely criticized Donald Trump over his alleged affair with porn star Stormy Daniels during the first debate Thursday night, accusing the former president of having the “morals of an alley cat" to describe his history of sexual immorality.

Biden's comments followed Trump's attack on Biden's son, Hunter Biden, who was recently found guilty on federal gun charges and has for years been a target of far-right conspiracy theorists.

Trump’s hush money trial revolved around an alleged affair with Stormy Daniels in 2006. In May, a Manhattan jury found Trump guilty of 34 felony counts of falsifying business records related to hush money payments made to Daniels ahead of the 2016 election to prevent her from publicizing the affair.

Biden's sharp remarks also referenced Trump's alleged affair and the sexual abuse civil lawsuit brought by writer E. Jean Carroll. A jury found Trump liable for sexually abusing Carroll last year, awarding her $5 million. Earlier this year, another jury determined that Trump had defamed Carroll, awarding her an additional $83.3 million.

Biden said:

“The crimes that you are still charged with — think of all the civil penalties you have. How many millions of dollars do you owe in civil penalties for molesting a woman in public?"

"For doing a whole range of things? Of having sex with a porn star...while [your] wife was pregnant?”

"What are you talking about? You have the morals of an alley cat."

Trump later denied ever having sex Daniels and described his hush money trial as “rigged and politically motivated.”

You can hear what Biden said in the video below.

Biden later repeated his new nickname for Trump in a post on X, formerly Twitter:

"Donald Trump is a convicted felon with the morals of an alley cat."

You can see his post below.

Many concurred.

In denying that he'd ever had a sexual relationship with Daniels, Trump flasely asserted that he ultimately lost his hush money case because prosecutors "moved a high-ranking official—DOJ—into the Manhattan DA’s office to start the case," suggesting he was politically smeared.

He was referring to Matthew Colangelo, who served as a senior official within the Department of Justice (DOJ) for the Biden administration but left to join the prosecution team led by Manhattan District Attorney Alvin Bragg.

Trump has continued to claim Bragg colluded with Biden and Attorney General Merrick Garland to ensure Trump's conviction even though Bragg's office is not under the purview or influence of Garland or Biden.