![Kate Upton Celebrates 21st Birthday: A Look At The Sports Illustrated Model's Sexiest Looks [PHOTOS] Kate Upton Celebrates 21st Birthday: A Look At The Sports Illustrated Model's Sexiest Looks [PHOTOS]](https://d.ibtimes.com/en/full/689858/kate-upton.jpg)
Kate Upton Celebrates 21st Birthday: A Look At The Sports Illustrated Model's Sexiest Looks [PHOTOS]
![David Hasselhoff on Twitter: "Now that's a curvacious Baywatch babe !! @ KateUpton @HHASSELHOFF See Hayley in the London fashion week + size rocks http://t.co/eVnfZ3DvSq" / Twitter David Hasselhoff on Twitter: "Now that's a curvacious Baywatch babe !! @ KateUpton @HHASSELHOFF See Hayley in the London fashion week + size rocks http://t.co/eVnfZ3DvSq" / Twitter](https://pbs.twimg.com/media/BfLSJ8LIcAAfeT9.jpg)
David Hasselhoff on Twitter: "Now that's a curvacious Baywatch babe !! @ KateUpton @HHASSELHOFF See Hayley in the London fashion week + size rocks http://t.co/eVnfZ3DvSq" / Twitter
![Kate Upton mimics Pamela Anderson as she poses with lifeguard float in string bikini | Daily Mail Online Kate Upton mimics Pamela Anderson as she poses with lifeguard float in string bikini | Daily Mail Online](https://i.dailymail.co.uk/i/pix/2012/07/10/article-2171494-14015F96000005DC-491_308x185.jpg)
Kate Upton mimics Pamela Anderson as she poses with lifeguard float in string bikini | Daily Mail Online
![Kate Upton mimics Pamela Anderson as she poses with lifeguard float in string bikini | Daily Mail Online Kate Upton mimics Pamela Anderson as she poses with lifeguard float in string bikini | Daily Mail Online](https://i.dailymail.co.uk/i/pix/2012/07/10/article-0-14010DB6000005DC-790_634x950.jpg)
Kate Upton mimics Pamela Anderson as she poses with lifeguard float in string bikini | Daily Mail Online
![Kate Upton mimics Pamela Anderson as she poses with lifeguard float in string bikini | Daily Mail Online Kate Upton mimics Pamela Anderson as she poses with lifeguard float in string bikini | Daily Mail Online](https://i.dailymail.co.uk/i/pix/2012/07/10/article-0-14010DC0000005DC-72_634x906.jpg)