Watch: How Khloé Kardashian and Tristan Thompson Celebrated Son Tatum's 3rd BirthdayTristan Thompson is focusing on his MVPs. After all, the basketball player and ex Khloe Kardashian celebrated their 3-year-old son Tatum Thompson's birthday with their daughter True Thompson, 7, as well as his and ex Jordan Craig's 8-year-old son Prince Thompson. Tatum and Prince, matching in beige T-shirts, were all smiles alongside True and their cousin Dream Kardashian, 8-who Khloe's brother Rob Kardashian shares with ex Blac Chyna-donning baby pink.