Tristan Thompson was a happy dad this weekend as three of his four children celebrated together - Kardashian style. "Big hugs and kisses for my little Tatum's Bday! I Love you forever young king ," Thompson, 34, wrote via Instagram Tuesday, July 29, referring to his youngest child, Tatum, who turned 3 on Monday, July 28. (Thompson coparents Tatum and daughter True, 7, with ex Khloé Kardashian, whom he split from in 2021 after a tumultuous on-and-off relationship.