Tristan Thompson is celebrating his “best friend” Khloé Kardashian. The Cleveland Cavaliers player, 33, wrote a heartfelt tribute to Khloé for her 40th birthday on Thursday.

On his Instagram Stories, Tristan shared several posts, starting with “Happy Birthday Khloé!!” and “You are my best friend.” He followed with a post showing Khloé with their daughter True, 6, saying, “You are the best mom.”

Tristan, who also shares a 1-year-old son, Tatum, with Khloé, ended with a photo of Khloé and his younger brother Amari, who has epilepsy and other medical conditions, calling her “the most incredible human being I’ve ever met.”

Many others also wished Khloé a happy birthday. After a recent heated conversation with Khloé on “The Kardashians,” Kim Kardashian sent her sister a sweet birthday message online.

“Welcome to the f—ing 40 club baby!!!!! @khloekardashian I feel like you have been waiting for years to finally be done with your 30’s and the time has now come,” Kim wrote. “I know this will be the best decade of your life filled with so much love and happiness! I’m so excited for you to experience this because I know how good it is, and no one deserves this more than you!”

She added, “What a crazy life we live! I couldn’t do it without you by my side! Thanks for being the best friend and sister a girl could ever dream of. Happy Birthday.”

Khloé’s mom, Kris Jenner, also posted a lengthy note on Instagram honoring her daughter.

“You are one of the most wonderful loves of my life, and I cherish each and every glorious memory we have ever made. You are the most amazing daughter and have been the greatest gift in life, but watching you as a mommy has been so remarkable for me,” Jenner, 68, wrote, sharing photos from throughout Khloé’s life.

“You are such a joyful, happy, funny slice of life and when I’m with you, you always make me feel so special and so happy to be around you,” she continued. “I love your strength and your sensitivity and your vulnerability and your support. Happy birthday, my beautiful girl and may all of your dreams come true. I love you beyond measure, more than I can ever explain in words, and you will always be my Bunny love, Mommy.”