​Kate Upton Horse: Upton Giggles During Model Shoot​​

Kate Upton really flaunted her bouncing assets during a recent modeling shoot where she posed topless on a horse, as the 21-year-old supermodel was seen giggling and stripping down to just a pair of underwear.

Upton begins the session fully clothed, with a zip down top, some sort of wraparound bottom, and the requisite bra and bikini bottoms.

Although Upton begins the session trying to keep her breasts covered with her hands, she soon realizes, there’s just no way to hide them.

Eventually, she is forced to release them, set them free. Although the video is censored, it’s reportedly that once uncovered, her “girls” are everything that Upton fans hoped — and expected — them to be.

Upton recently celebrated her 21st birthday by spending time with her uncle, Republican Congressman Fred Upton of Michigan, and his friend Kevin McCarthy, the GOP Whip.

She has also been filming scenes for the movie The Other Woman, in which she will make her first real transition into acting when she stars alongside Cameron Diaz, Leslie Mann and Nikolaj Coster-Waldau.

The film comes out in April 2014.

As far as the model’s personal life goes, the star has recently been linked to “Dancing with the Stars” pro Maksim Chmerkovskiy.

The two were spotted having dinner together recently in New York City.

“It was a very intimate meal,” a source told Us Weekly of the two’s night out.