Heidi Klum must have really enjoyed the tropical vacation she recently took. How do we know? Because she proved it to us. The model posted a picture on Twitter that showed her sunbathing topless with sand and sea in the background. She captioned the picture with the words, "Island Speed" but chose not to disclose the location.

Klum is seen lying face down on a sun-lounger in just a pair of black tiny bikini bottoms. From the picture, it is evident that Klum is really enjoying the time as she has a calm and serene smile on her face. The 39-year-old showed off her svelte torso and long legs and also confidently flashed a hint of side-boob, which is the latest rage.

The trend of flashing the side-boob is hot even on the red carpet with celebs wearing high necked dresses but giving a little peek of the sides. The trend has taken over the glitz of a full cleavage and now side-boob is even being called the new cleavage

The Project Runway judge must be getting her glow and energy replenished for the upcoming holidays with new bodyguard boyfriend Martin Kristen and children Leni, 8, Henry, 7, Johan, 5 and Lou, 3.

This is the first festive season that the children will be spending without their father and Klum's former husband Seal. The former couple split in Jan. 2012 after seven years of marriage. But they do have Kristen for company who seems to dote on them and the kids surely aren't complaining.

"They like him very much. This is also one reason why I'm so fond of him. He's been helping me for four years now. And he takes wonderful care of the kids. He plays with them, he protects them. I trust him." Klum told Bunte magazine in November.