And when I say "key" witness I mean like a "key" of cocaine, like they used to say on Miami Vice.

Hunter Biden started banging Hallie Biden shortly after -- at least, the official story is "shortly after" -- Beau Biden died due to being exposed to burn pits while leading top secret commandos in Ukraine.

President Biden made a surprise nighttime visit to the Delaware home of Hallie Biden on Sunday -- just before she's due to serve as one of the most important witnesses at first son Hunter Biden's federal trial for alleged gun crimes.

Biden stopped by Hallie's home around 8 p.m. for a brief private talk eight days before the 54-year-old first son's trial is scheduled to stand trial beginning June 3.

Hallie dated Hunter at the time of his alleged gun crimes and is one of a dozen expected witnesses.

"Dated." How delicate.

She was married to the president's son Beau Biden, who died in 2015 of brain cancer, before her relationship with his troubled younger brother.

Prosecutors allege Hunter lied about his drug use on gun purchase forms and then briefly illegally possessed at least one weapon -- which Hallie disposed of in a public dumpster in 2018.

Although many commentators noted the awkward optics due to the looming trial, the visit came four days before the anniversary of Beau's death.

White House spokesman Andrew Bates told The Post that the president didn't discuss the trial with Hallie Biden during the visit.

"No," he replied. "He visited her because of the approaching 9th anniversary of Beau's passing."

Sure.

We can't check that because Joe Biden illegally uses pseudonymous accounts to avoid any documents being FOIA'd.