"How do you not have a tummy??" a user commented. "I'm 4 months into my pregnancy and my tummy is huge you look great tho!"
Gigi, 25, replied to the fan and exposed her nifty style trick.
"This angle and the really baggy jumpsuit make for an optical illusion," she wrote. "From the side it's a different story! haha -- wishing u the best! x"
While the model has been rather private about her pregnancy journey thus far, she briefly mentioned it during an Instagram Live chat with Maybelline makeup artist Erin Parsons in May.
"People think I do fillers on my face, and that's why my face is round -- I've had this since I was born," Gigi said at the time. "Especially Fashion Month, when I was already, like, a few months preggo, you know."
Waiting for your permission to load the Instagram Media.
"Obviously, we wish we could've announced it on our own terms, but we're very excited and happy and grateful for everyone’s well wishes and support," she said.
Although Gigi and Zayn haven't publicly revealed the sex of the baby, TMZ confirmed the couple is expecting a girl.
As fans know, the two have had an on-again-off-again relationship for years and reportedly got back together in December 2019. Gigi and Zayn fueled rumors they had rekindled their romance when they were spotted in New York City in January.
The pair confirmed they were officially back together after Gigi shared a sweet Valentine's Day tribute to Zayn, posting a photo of the former One Direction singer from December.