The Chicago Bulls player, 31, opted to not share any public messages in honor of the special occasion not long after his paternity scandal aired on The Kardashians.
Khloé celebrated at her mom's $20 million mansion in Hidden Hills with family and friends, wearing a sexy pink latex dress.
Last year, they both shared heartfelt messages for each other on their birthdays, with him describing Khloé "as an amazing partner, mommy and best friend but also being the kindest, caring and most loving human being I've ever met."
Khloé and Tristan split in June 2021. RadarOnline.com is told the two have made co-parenting 4-year-old daughter, True Thompson, their top priority amid their breakup drama.
In December, fitness model Maralee Nichols filed a lawsuit against Tristan, alleging that he was the father of her baby boy, Theo. She said he was conceived while the athlete was still in a relationship with Khloé.
By January, Tristan had owned up to it and apologized to the Revenge Body alum in his public statement after paternity results confirmed he was indeed the dad of baby Theo.
Khloé later broke down in tears after Kim Kardashian informed her of the lawsuit during the June 16 episode of The Kardashians.
"No matter what, everything is going to be OK. We really thought he had changed. Like, I was his biggest supporter. But if this isn't more clear, the most clear situation, I don’t know what is," Kim said as she tried to comfort her sister.
"I find out what Tristan is doing with the rest of the world. A courtesy would be not doing it. But fine, if you do it, you are not even going to give me a f---ing heads-up before the rest of the world?" the Good American founder also vented about the ordeal. "It is just an additional slap in my face. It is humiliating. I am embarrassed."
Despite the drama that's gone on, the former flames were recently seen putting on a united front while out and about with family.
Khloé also mentioned her dreams of a better future on the show, stating, "One day, I will have the fairy tale that I hope to have."