NFL star Patrick Mahomes was more nervous about proposing than playing in Super Bowl

The Kansas City Chiefs quarterback says proposing to longtime girlfriend Brittany Matthews had his "heart racing" compared to playing in the Super Bowl.

Crouching under center in a tense fourth quarter in the Super Bowl was nothing for Patrick Mahomes compared to getting down on one knee and proposing to his longtime girlfriend.

The Kansas City Chiefs star quarterback and reigning NFL MVP was asked what made him more nervous, the fourth quarter of the Chiefs' comeback win over the San Francisco 49ers in this year's Super Bowl or his proposal to Brittany Lynne Matthews at the team's stadium after getting his Super Bowl ring earlier this month.

Staging a fourth-quarter comeback in the Super Bowl was not as nerve-wracking for Patrick Mahomes as proposing to longtime girlfriend Brittany Matthews this month. Andy Lyons / Getty Images

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"Probably proposing, I would say," Mahomes told 610 Sports Radio in Kansas City, Missouri. "You don't think it's going to be nerve-wracking, especially when you've been with someone for so long, but before you get on that knee, your heart's racing, I promise you that."

Mahomes, 24, proposed to Matthews, 25, at Arrowhead Stadium after the Super Bowl ring ceremony on Sept. 1 in one of the suites inside the stadium.

Matthews shared a photo on Instagram of a suite filled with candles, flowers and a glowing sign that said “WILL YOU MARRY ME.”

Brittany Matthews shared a photo of the elaborate proposal from longtime boyfriend Patrick Mahomes at Kansas City's Arrowhead Stadium.@BrittanyLynne / Instagram

She also showed off the enormous emerald cut diamond given to her by Mahomes, who certainly can afford it after signing the biggest contract in NFL history during the offseason at 10 years and a reported $503 million.

A day after the engagement, she wrote a heartwarming message to Mahomes on Instagram.

"On a day that was meant to celebrate you, you turned it into celebrating us," she wrote. "It’s always us, it’s always you and me. The words you looked into my eyes and said to me at this moment, will NEVER leave my mind! You made this day perfect, you took my entire breath away and I could not have imagined anything better. I love you, forever and always! Cheers to spending our lifetime together and an inseparable bond."

The couple have been together since their days at Whitehouse High School in Texas when Matthews was a junior and Mahomes was a sophomore. Mahomes, who is the son of former major league pitcher Pat Mahomes Sr., wasn't even a quarterback yet as he played safety on the Whitehouse football team at the time.

Athletics has been a shared passion for the two, as Matthews is a former professional soccer player and now is a certified fitness trainer.

Now that he's set to tie the knot, Mahomes has been getting tips about married life from Chiefs fullback Anthony Sherman and wide receiver Gehrig Dieter.

"Both those guys have done it the right way, so they kind of kept me in tune on what's the right steps and the right way to go," Mahomes told the radio station.