It’s time. The University of Texas' football team exposed itself in Dallas and Longhorn Nation must ask whether Mack Brown is the man to lead this program any longer.

Most of the Longhorns failed to even show up at the State Fair. Those who did got fried like so many Oreos, bananas, corn dogs and butter — losing 63-21 to rival Oklahoma.

Mack Brown showed up. I saw him on the sideline looking . . . well, confused.

There is no need to dissect a game that Texas gave up on in the first quarter.

Instead, let’s ask some hard questions. Has Mack Brown stopped coaching — is he ready to retire? Mack, you can only be embarrassed by Oklahoma so many times before being fired at Texas.

You’ve been out-coached again by Bob Stoops. You’ve won a national championship, you deserve the right to leave on your terms. This is gut-check time.

How did Texas' defense get so bad so fast? Defensive coordinator Manny Diaz knew his unit had problems with tackling and coverage when it played Wyoming. Things have only gotten worse.

Are they actually practicing this stuff?

How did Texas’ offense get so bad so fast? The defensive virus must be contagious. One stat to think about: At the end of the first half, 15th-ranked Texas had almost as many points (two) as first downs (three). No. 13 Oklahoma, with 400 yards of offense, 200 yards rushing and 36 points, owned the ball for two-thirds of the first half.

Did anyone actually watch the second half? The stands were emptying before the half ended. The football game was all the carnival midway anyone needed. And UT is done. There is little else to say outside of this: Longhorn Nation is not happy, and Mack Brown needs to be looking over his shoulder.

Because this kind of embarrassment is not anywhere in the neighborhood of Texas’ standard.