Brittany Matthews Reacts to Boyfriend Patrick Mahomes’ Record-Setting Deal: 'I'm So Proud of You'

Patrick Mahomes and girlfriend Brittany Matthews are on top of the world after the Kansas City Chiefs quarterback this week signed the most lucrative deal in sports history.

According to ESPN's Adam Schefter, Mahomes and the Chiefs agreed on a $450 million contract extension on Monday that could eventually net the quarterback up to $503 million over 10 years.

It's a jaw-dropping contract for sure, but it could be worth every penny: The 24-year-old led the Chiefs to a Super Bowl win over the San Francisco 49ers in February and has long been labeled one of the league's most talented quarterbacks.

After the record-breaking deal was announced, Matthews posted a selfie with her beau to her Instagram Story with a simple message that read "I'm so proud of you." Matthew and Mahomes have been together since they met in Texas as 10th graders, according to Yahoo Sports.

Matthews — who operates her own fitness company, Brittany Lynne Fitness — posted several other pictures from the signing with the caption "Let me tell y’all about my best friend, he earned that ish." The message also included pink heart emoji.

RELATED: Patrick Mahomes Makes History as He Signs $450 Million Contract Extension

Brittany Matthews/Instagram From left: Brittany Matthews and Patrick Mahomes

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But Matthews wasn't the only one to celebrate her boyfriend's big day.

Kansas City Head Coach Andy Reid called Mahomes one of the most "incredible athletes and special people" he's been able to coach throughout his storied career.

"He's a natural leader and always grinding, whether that's on the field, in the weight room or watching film," Reid said. "He wants to be the best."

Los Angeles Lakers legend Magic Johnson also reached out to Mahomes to offer his congratulations.

RELATED VIDEO: Patrick Mahomes Makes History as He Signs $450 Million Contract Extension

Patrick Mahomes Makes History as He Signs $450 Million Contract Extension

The Kansas City Chiefs have signed Patrick Mahomes to a 10-year contract extension which is said to be the "largest contract in sports history," according to his agent

"Congratulations to @PatrickMahomes on his record-breaking $450 million deal - which could go up to $503 million with incentives!" Johnson wrote on Twitter.

Follower NFLer Dez Bryant simply said Mahomes was "different" than any of league's other quarterbacks.

"He different and it’s clear," Bryant wrote in a tweet. "He’s a real down to earth person... to me that’s why he’s a winner."