It's hard to believe that Naya Rivera gave birth to a baby boy in September.

On Tuesday night, the Glee star stepped out for the Vanity Fair and FIAT Toast to Young Hollywood event in Los Angeles, California, wearing a jaw-dropping white gown that showed off her ample cleavage.

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"Absolutely l❤️ved this @TadashiShoji look tonight for the @VanityFair young Hollywood party!" Rivera Instagrammed.

The 29-year-old actress also credited breastfeeding her son, Josey Hollis Dorsey, for how her breasts looked in the dress. "Shout out to my son for the lopsided boobs," she quipped. "LOL #breastfeeding #momlife He is SO worth it."

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Rivera's husband, Ryan Dorsey, must have been babysitting because the new mom brought along fashion stylist, Taylor Jacobson, as her date to the party.

The cleavage-baring gown isn't the first plunging neckline Rivera has worn since welcoming her new baby. At a Golden Globes after party in January, she stepped out in a Pamella Roland gown that also flaunted her sexy curves.

While her post-baby styles are certainly scantily-clad, nothing has been quite as provocative as when she posed nude while pregnant. After posting pics from a shoot in August, Rivera had to fight off claims that she was copying her frenemy, Kim Kardashian.

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"I chose to share pregnancy photos because I think this is a very beautiful and special time in my life," she Instagrammed at the time. "Media outlets know that when you give your photos and an interview to run a story you never get a choice as to when it runs. So trying to make something out of nothing based on stupid assumptions is awful. Such a shame. Especially when it comes to a woman and her beautiful pregnancy journey."

Here's a look at the nude pregnancy pics: