Lily McMenamy's topless runway walk was the talk of Fashion Week.

The 18-year-old daughter of 1990s supermodel Kristen McMenamy appeared in the show for Marc Jacobs's fall collection at the Lexington Avenue Armory in New York City Thursday night.

Yet Lily McMenamy was wearing a bit less than the rest of the models.

Dressed in black hot pants, black pumps and elbow-length black fishnet gloves, McMenamy was topless.

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Lily McMenamy made her modeling debut at the Saint Laurent show for Paris's Fashion Week back in the fall. Work for Karl Lagerfield at Chanel---who walked Lily McMenamy down the aisle at her wedding---and a photo shoot for T Magazine, soon followed.

"I feel like I've had a lot of experience for an 18-year-old," Lily McMenamy told The Gloss. "I grew up quite fast."

Twitter user Michelle McCool thought Lily looked great,

"Lips like her mom," McCool tweeted on Friday.

"It's all in the genes, so they say," wrote Tim Yap. "Who knew Kristen McMenamy has a model-daughter?"

But not everyone on Twitter was impressed with Lily McMenamy's topless catwalk trip.

"Is it me or is Lily McMenamy particularly not pretty for a runway model?" tweeted Mike Andrick. "Helps to have a supermodel mom, I guess."

Brian Lerner was equally uncomplimentary on Twitter.

"Ugly girls make a killing getting paid to be runway models," he wrote.