'Riverdale's' KJ Apa expecting first child with Clara Berry

May 20 (UPI) -- Riverdale star KJ Apa and model Clara Berry are expecting their first child together, the couple announced on Instagram.

Apa uploaded to Instagram on Wednesday an uncaptioned photo of himself sitting on a couch with Berry who is displaying a baby bump.

"Rivers soon to bestie," fellow Riverdale star Vanessa Morgan commented on the post in reference to her 4-month-old son River.

Berry, on her Instagram page, posted a collection of maternity photos.

"She's pregnant btw," Apa commented on the post to which Berry replied, "We are."

Apa, 23, and Berry, 27, were first linked together in August. Apa stars as Archie on the hit CW series.

Morgan, in April, brought her son to the set of Riverdale. She shares River with her estranged husband, professional baseball player Michael Kopech, who filed for divorce in July.