The 21-year-old supermodel Kate Upton went topless during a recent modeling shoot on a horse, TMZ reported.

In a video obtained by TMZ, the model attempted to cover herself as she takes off her top revealing her bare breasts, but quickly realizes it was useless.

Upton made headlines recently when rumors swirled of the supermodel celebrating her 21st birthday with alleged new boyfriend "Dancing With The Stars" Maksim Chmerkovskiy. Us Weekly reported from "multiple insiders" have confirmed Upton and Chmerkovskiy's couple status. One source told the magazine "they were set up through friends. They just started dating."

The rumored couple was caught dining at Scalinatella in New York City's Upper East Side neighborhood.

"They were very canoodly," an eyewitness told Us Weekly. "It was a very intimate meal."

However, sources told E! that Upton and the dancer are just good friends.  Upton neither confirmed or denied the reports.

Upton was also rumored to have dated MLB pitcher Justin Verlander. She reignited rumors that the two were previously an item when she sent a happy birthday tweet to Frank Viola III, a friend of Verlander, on Wednesday.

The supermodel tweeted an eCard yesterday that read "Happy birthday to a friend of a friend who I now like more than the original friend." She reportedly deleted the tweet with the eCard less than 45 minutes later and replaced it with one that didn't include the dig at Verlander.

Upton and Verlander never admitted that they were dating, but her tweet caused social media users to speculate about their alleged relationship. Upton has been featured on the covers of Sports Illustrated, Vogue, GQ and Vanity Fair.

Warning: The video of Upton's photoshoot contains nudity. Watch it here.