The couple were there with Klum's kids and parents to celebrate her daughter Lou's 3rd birthday on October 10, reported Us magazine.
The 39-year-old mother-of-four enlisted her new man's help to party with her four kids: Leni, 8, Henry, 7, Johan, 5, and birthday girl Lou.
"It really is the happiest place on earth!" she tweeted with a photo of herself smiling in front of a Mickey Mouse Ferris wheel.
The Project Runway host rode a merry-go-round with her little girl, who was dressed up like an adorable princess. Klum and Kristen wore matching outfits of black shirts and dark shades.
In September, Klum confirmed her relationship with Kristen, her former bodyguard, after separating from husband Seal. "I trust him with my children's life. He's a great man... And we just got to know each other from a completely different side," she said about Kristen.
