WASHINGTON — Did they, or didn’t they?

For a surreal moment — just as Joe Biden prepared to deliver his State of the Union speech — his wife Jill Biden stole the show by appearing to plant a kiss smack on the lips of the vice president’s husband.

It happened in a heartbeat: after sweeping into Congress to cheers, the first lady made her way over to the second gentleman, Doug Emhoff, and clasped his hand.

Then, in a moment destined to go viral, they leaned in for a friendly embrace — but at least one of them appears to have miscalculated and the result was a kiss either on, or very, very close, to the lips.

“Smooch of the Union,” teased the New York Post tabloid — zooming in on photos of what it declared without a doubt to have been a kiss on the mouth.

Other close-ups of the embrace seemed to show Biden’s kiss landing just to one side of Kamala Harris’s husband’s mouth.

But Fox News — a frequent critic of Biden’s administration — pounced on the apparent slip-up without the shadow of a doubt.

And Donald Trump’s former advisor Kellyanne Conway shared a picture of the smooch with similar delight, quipping: “Wow, Covid really is over.”