Looking relaxed and happy, Heidi was in casual mode on the sunny outing. The model wore a pair of pale jeans and trainers with a t-shirt and top, and her unstyled blonde hair hung loosely around her shoulders.
Heidi and Martin have been dating since last September. But she's had plenty of time to get to know him as he worked as the family bodyguard for the last four years.
Although the German supermodel tried to keep her new romance under wraps at the beginning, since going public she has spoken highly of her new man. To TV host Katie Couric she confessed: "He's been with our family for the last four years. He's cared for our entire family, mostly for our four children, helped us tremendously. I trust him with my children's life. He's a great man, you know, and we just got to know each other from a completely different side."
At first the blonde beauty said she didn't know where the romance was going. But it seems from Martin's constant presence in her life that he is a permanent fixture. The pair are often seen grocery shopping together and Martin has been spotted taking Heidi's eldest daughter Leni to gym class and he's been on several family outings with the Project Runway host and her brood.
The catwalk queen told chat show host Ellen DeGeneres that she is "very happy" in her new romance. She also revealed that she has watched Whitney Houston and Kevin Costner's 1992 film The Bodyguard - about a singer who falls for the man employed to protect her - since she started seeing Martin, because of the parallels in the relationship. She confessed: "I've actually watched that movie since [I started dating my bodyguard]. I had to!"