Kevin Costner is flexing his status after his ex-wife got engaged to a former friend of his ... getting the royal treatment in New Orleans for Super Bowl LIX.

The "Yellowstone" star is enjoying the Crescent City before Sunday's big game, riding a pedicab through the streets.

Looks like Kevin's joining the growing list of celebs in town to see the Kansas City Chiefs take on the Philadelphia Eagles in the year's biggest sporting event.

Kevin needs all the distractions he can get right now ... his ex-wife Christine Baumgartner just got engaged to financier Josh Connor, and she just showed off her huge diamond ring.

Costner is going to see someone win a ring live and in person Sunday ... and it seems Christine and Josh will have to settle for watching the game on TV at a Super Bowl party.

Touchdown, Kevin!!!