Following reports that recently divorced supermodel Heidi Klum has been dating her 39-year-old Australian bodyguard, Martin Kirsten, for three months, friends tell us, “She has indeed become very close to him.” In Touch first reported the pair were recently spotted together on vacation in Sardinia, Italy. A friend of the German beauty, also 39, tells us, “After going through such an ugly divorce with Seal, Heidi’s inner circle has shrunk, and there are only a few people she trusts and feels comfortable with. Martin is one of those people. He has protected her and her family — her kids love him — for four years, and she relies on him. They became closer this summer. Her friends have noticed something is going on, but it’s hard to define it because he’s worked with her and her family for a long time.” After being married for almost seven years, Heidi and Seal separated in January. Three months later, the beauty filed for divorce. They share three biological children; Heidi also has a daughter from a previous relationship.