Here's what happened ... Romo was doing the play by play with fellow commentator, Jim Nantz, during the Kansas City Chiefs' 20-14 loss to the Las Vegas Raiders on Christmas Day. Taylor was back in her VIP suite for the game at Arrowhead Stadium cheering on Travis – her boyfriend, of course, and the Chief's tight end.

But, Romo got it all twisted when Taylor's image flashed on the TV screen, accidentally calling her Travis' WIFE!!

Check out the video posted on Instagram ... Taylor, wearing a Santa hat with Travis' number "87" on it, stands up to root for her beefy lover on the field.

Romo then blows it, but soon catches himself and corrects his mistake, saying, “And his wife loves it, I mean, girlfriend.”

Nantz doesn't let Romo off the hook, pointing out, “You’ve been down this road before."

Unfortunately, Romo has. While calling the Chiefs game against the Buffalo Bills last week -- Romo made the same boo-boo.

Once again, the camera panned on Taylor clapping in the audience when Romo said, "As you see, Kelce’s wife, Taylor Swift, in the audience." He caught his blunder there, too, quickly adding, "I'm sorry. Girlfriend!"

Another broadcaster quipped, "Not yet," while chuckling at Romo's gaffe.