Joe Biden shut down a reporter for asking what he called a “classless” question about his son Hunter allegedly fathering a child with a woman in Arkansas.

The Democratic presidential hopeful was asked Thursday about a DNA test that, according to court papers, confirmed Hunter is the father of a 15-month-old child.

The baby’s mother, Lunden Alexis Roberts, 28, filed a paternity suit against the former vice president’s son in May.

“I’m wondering if you have a comment on this report, and court filing, out of Arkansas that your son Hunter just made you a grandfather again,” Fox News reporter Peter Doocy asked at a press conference.

Biden, 77, quickly halted the line of questioning, snapping, “No, that’s a private matter and I have no comment.”

“Only you would ask that,” he added, pointing at Doocy.

“You’re a good man … Classy,” Biden said with a wry smile.

Hunter, 49, has denied having sex with Roberts.

In court documents filed Wednesday, Roberts’ lawyers argued a DNA test Hunter took established with “scientific certainty” that he is the father.