Christina, 35, and Tarek, 37, were seen shooting scenes in Anaheim, California.
The mother-to-be, who is expecting her first child with husband Ant later on this year, showed off her tiny baby bump in a long-sleeved top.
It's the second time that Christina has been seen out ever since she announced her joyous pregnancy news on Friday, March 22.
Tarek appeared unbothered while standing next to his ex-wife. He repeatedly checked his phone on set while sporting a blue polo and dark pants.
Do you think Tarek is really happy for Christina? Sound off in the comments.