Patrick Mahomes/Instagram Jackson and Patrick Mahomes
Patrick Mahomes' younger brother is growing up!
The Kansas City Chiefs quarterback, 25, shared a sweet post on Saturday to celebrate his brother Jackson's 21st birthday. "Lil bro ain't so little no more! Happy 21st @jacksonmahomes," he wrote alongside a photo of the pair together, adding the hashtag "much love."
Jackson also got a special shout-out from the NFL player's fiancée Brittany Matthews.
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"Happy Birthday to my BESTIEEEE! You are the best Brother, Son, Manager, Bestfriend and an even better Uncle to Sterling, Steel & Silver!" she wrote in her own tribute, referencing daughter Sterling Skye as well as the couple's two dogs.
"We love you so much, and are so incredibly thankful for you!! Cheers to freaking 21!!!!!!🥂🎉❤️," Matthews added.
The 25-year-old fitness trainer went on to share a fun throwback image of herself with the Mahomes family. In a message to the birthday boy she jokingly wrote, "@jacksonmahomes glad your swag has improved."
Brittany Matthews/Instagram Brittany Matthews and Patrick Mahomes with his family
Matthews and the NFL star recently celebrated another important moment in their life: her first Mother's Day since welcoming their daughter in February.
Last week, the new mom shared several sweet photos of their baby girl. "Dear Sterling, thank you for making me a mommy and being the biggest blessing EVER, Mommy & Daddy love you more then [sic] you will ever understand," she captioned the post.
The quarterback also shared a tribute to Matthews, writing on Instagram, "Happy 1st Mother's Day!"
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Brittany Matthews/instagram Brittany Matthews and Patrick Mahones with daughter Sterling Skye
Last month the couple — high school sweethearts who celebrated 9 years together earlier this year — stepped out with their daughter as they celebrated the first home game for the Kansas City NWSL: a professional women's soccer team co-owned by Matthews.
"Chillin with the owner ⚽️," Mahomes captioned one cute family photo.
"Get you a fiancé who rocks your name like you rock his 💯💕💕 @patrickmahomes," Matthews wrote alongside another post, which showed the football player wearing a jersey with name on it.