Kristin Cavallari once pumped breast milk in an airport bathroom Credit: Courtesy Kristin Cavallari/Instagram

Coming clean! Kristin Cavallari doesn't just sit back with her luggage and read a book during flight delays. Now pregnant with her third child, the Laguna Beach alum fessed up to pumping breast milk in an airport bathroom in a hilarious throwback photo she posted on Thursday, July 2.

"Pumping in airport bathrooms. Feel like I JUST put all my pumping essentials away won't be long before I'm at it again," Cavallari, 28, captioned via Instagram. "#TBT #goodtimes #gottadowhatyagottado." (Kourtney Kardashian previously pumped following her 36th birthday bash in Las Vegas on April 18!)

Cavallari and NFL husband, Jay Cutler, are parents to sons Camden, 2, and Jax, 13 months. In May, the fashion designer revealed that they are expecting their third child together.

"It flies by so quickly. It kind of makes me sad. But they’re both at such fun ages now. They're able to start playing together a little bit now that Jax is 1. It's really nice. I feel like we’re in a really good place. They're both great kids. They’re just a lot of fun. So we're really lucky," Cavallari told Us Weekly and other reporters at the 12th annual JDRF L.A. Imagine Gala on May 9, just days before announcing her pregnancy.

She added: "[Camden's] very protective and very sweet, but he also gets a little upset when Jax tries to take his toys and messes with his stuff. He gets a little territorial with some stuff, so it's kind of funny."

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