Judging by The Kar-Jenners’ Instagram Stories, they’re celebrating many birthdays this March. As Kris Jenner wishes her pal Kathy Hilton a Happy Birthday, the father of two of her grandchildren, Tristan Thompson, is also getting birthday shout-outs from more of the famous family. Despite Tristan Thompson and Khloé Kardashian‘s relationship coming to an end, the Kardashians star took her ex’s birthday as an opportunity to show him some love this March. Khloé and Tristan are parents to True and Tatum Thompson, who are coming up six and two years old this year. Tristan Thompson’s birthdayBasketba…