The HGTV stars both attended the event at the Wallis Annenberg Center for the Performing Arts. Christina arrived with her new husband, Ant Anstead, while Tarek showed up separately with their daughter, Taylor.
Christina wore an animal print dress, which was perfect attire for the Discovery series, which follows the heartwarming stories of a cast of African wildlife including lions, zebras, baboons and cheetahs over the course of a year.
Many of the storylines in "Serengeti" focus on the unconditional love between parents and children ... which is perfect for Christina, who was showing off her growing baby bump!
The 36-year-old star of "Christina On the Coast" is weeks away from giving birth to her first child with 40-year-old Ant.
She already shares 3-year-old son Brayden and 8-year-old daughter Taylor with her ex-husband. Ant is also a father to a 12-year-old son and 15-year-old daughter from a previous relationship.
Sources at the event tell The Blast the Ansteads and Tarek were seated on opposite sides of the theater during the screening of "Serengeti," which featured a live performance by the Hollywood Symphony Orchestra as the soundtrack for the first episode.
After the screening ended, we're told Tarek, along with the ex couple's daughter, crossed the aisle and said hello to his ex-wife and her new husband.
We're told the stars all appeared to be very cordial, and Tarek even shook Ant's hand.
Tarek was probably in an especially good mood because it was just announced he will be getting his own standalone series on HGTV, "Flipping 101."
"Serengeti" is produced by "Idol" creator Simon Fuller and narrated by Academy Award winning actress, Lupita Nyong'o.
The 6-part series premieres on Sunday, August 4 at 8:00pm ET/PT.