Which Nearly 40-Year-Old Reality Star Tweeted This Killer #Bodysurfing Photo of Herself in a Skimpy Bikini? (PHOTOS)

That incredible bikini body belongs to none other than statuestesque 39-year-old Project Runway host, Heidi Klum. Just looking at her, we can hardly believe she's a mother of four — then again, she wasn't nicknamed "The Body" for nothin'! For more enviable celebrity bikini bodies, click here!

Heidi will be a judge on America's Got Talent this summer!