Kansas City Chiefs star Patrick Mahomes is making headlines for signing a 10-year deal worth $500 million — but the 24-year-old Super Bowl MVP won’t be enjoying the fruit of his labor alone.

Celebrating on Instagram on Monday, the QB’s longtime girlfriend Brittany Matthews, also 24, bragged about his accomplishment, telling her half a million followers: ‘Let me tell y’all about my best friend, he earned that ish.’

High school sweethearts Mahomes and Matthews have been together for over eight years, with Matthews — a personal trainer and former soccer player — supporting Mahomes since the beginning, back when Mahomes was still playing high school baseball.

Like Mahomes, Matthews is from Whitehouse, Texas, where she was raised by mother Diana Massey and father Scott Matthews.

She attended Whitehouse High School, which is where she and Mahomes met and started dating as teens.

Their earliest Instagram photo together is from December 2011, in which Matthews sits on Mahomes’ lap and refers to his as her best friend — but the pair didn’t officially get together until March of 2012.

They were both heavily into sports in their high school days, with Matthews cheerleading and playing soccer and Mahomes doing both football and soccer.

In throwback snaps, she is seen cheering him on at games, wearing his jersey at a baseball game and referring to him lovingly as ‘my little pitcher.’

She was there as he excelled at football, too, rooting for him from the stands.

‘She has been supportive of me in whatever I do even before I played quarterback in high school,’ Mahomes told Utterly Patriots in 2016. ‘She has been my No. 1 fan since the beginning. Her support means the world to me.’

They also went to several school dances together, including prom. Old photos show baby-faced Mahomes and Matthews posing together in formal attire, including for prom in 2013, when Mahomes matched his teal bowtie to Matthews’ shoes.

The two transitioned to a long-distance relationship during college, when Matthews went just 20 minutes away from home to UT Tyler, where she studied kinesiology. Mahomes, meanwhile, went to Texas Tech, which is 400 miles away in Lubbock.

But they continued to support one another and text often, especially on games days.

Matthews continued her athletics in college, playing for the school’s soccer team. There, she earned all-region honors after her senior season and is second all-time in program history with 78 points and her 31 goals, according to the The Morning Telegraph.

‘I am extremely proud of the level of play she has gotten to because all of it is from hard work,’ Mahomes told Utterly Patriots. ‘Her competitive nature is one of the many things I love about her. She hates losing and wants to be the best. She works extremely hard to be great and it inspires me to work just as hard.’

‘We feed off of each other,’ Brittany, who is 5’5″ to Mahomes 6’3″, added. ‘He’s an incredible leader and player and I’ve learned a lot from him.

‘We give each other advice and he is always being positive with me to motivate me when I need it. I’m constantly letting him know that he’s not the only one breaking records. We’re having a great time with everything that is going on in our lives. He’s doing big things right now and so I am.’

They graduated in 2017, with Mahomes joining the Chiefs and Matthews moving even further away to Iceland.

She signed with the Iceland pro team of UMF Afturelding/Fram, which is based in Mosfellsbaer, north of Reykjavik, and moved there after graduation.

She only seems to have played for a single season, though, before she decided to make a professional shift.

‘By the end of my first season, I truly began to fall in love with being in the gym more than being on the soccer field,’ she said on her website. ‘Playing sports my whole life got me into fitness and playing in college taught me about strength training, wellness and maintaining peak fitness to perform at an elite level.’

A certified personal trainer, Matthews then formed her own fitness company, Brittany Lynne Fitness, where she offers her training services.

‘”Training like Britt” means many things — working hard, staying dedicated, not making excuses, and most of all, no BS!’ she says on her site. ‘These programs are designed to tone, grow muscle and get STRONG. Don’t be afraid to lift heavy and push yourself!’

With her expertise, she even helps Mahomes with his eating habits.

‘Eating-wise, I’m blessed that my girlfriend is [big on] nutrition so she helps me out with that — she’s [about] fitness,’ he told Yahoo Sports.

The two are no longer long distance, and live together in Kansas City, where Mahomes bought a $1.925 million house.

‘Setting down roots in Kansas City was huge for us. I think the people are what we love the most about Kansas City,’ he told Bleacher Report. ‘We’re trying to be here for a long, long time.’

Together, they have two dogs, a pit bull and a Cane Corso named Steel and Silver. The dogs show up in the pairs’ Christmas cards, and they even have their own Instagram account with 156,000 followers.

Matthews continues to support Mahomes at games, and sometimes her mother and brother come to join her at the stadium.

On March 31, Mahomes celebrated their eight year anniversary on Instagram — prompting some commenters to ask if an engagement was in their future.

After similar questions were posed on their anniversary in 2019, Matthews replied: ‘To everyone that’s gonna ask when we are getting married, the answer is whenever we want.’