Patrick, Brittany Mahomes Sit Courtside In Dallas For NBA Finals Game 3

Patrick Mahomes rocks a Kansas City Chiefs jersey on Sunday, but he's a Texas native at heart ... and that's why the 3x NFL MVP pulled up with his wife Brittany to cheer on the Dallas Mavericks for the pivotal third game vs. the Boston Celtics in the NBA Finals!

The 3x Super Bowl champ was spotted courtside (where else?!) with Britt at American Airlines Center ... where the couple was all smiles for the cameras.

It's not the first playoff game the Mahomeses have attended ... they were also in the building for a Western Conference Finals tilt between the Mavericks and Minnesota Timberwolves.

That's the game where they brought along Travis Kelce -- and Taylor Swift's boyfriend was booed (Trav ain't from Texas)!

The Mahomes weren't the only famous duo catching the NBA Finals ... Dirk Nowitzki and Steve Nash, former Mavs superstar teammates, were also enjoying their courtside seats.

In fact, there was a funny moment between the two NBA legends ... cameras caught Nowitzki elbowing Nash in the chest as he tried to get the Hall of Famer fired up during the game.

Dallas Cowboys legend Emmitt Smith was also there, lounging with Dirk and Nash. Texas musician Jus Lyons AKA GuitarSlayer also performed at the game.

Unfortunately, the Texas celebs had to watch the Mavericks lose the critical game, falling down 3-0 in the series, pushing them to the brink of elimination.

Luka Dončić fouled out with several minutes left in the 4th and that was it.