What’s really in those Milk Shakes? Heidi Montag, Spencer Pratt, Kim Kardashian, Khloe Kardashian, Kourtney Kardashian and Perez Hilton seemed to be having way to much fun as they appeared at “Millions Of Milkshakes” to make their own signature shake. Perez was also there promoting his new book, “Red Carpet Suicide.” At one point, Heidi and Perez laughed at a display picture of Miley Cyrus holding a milkshake. Heidi also attempted to make her own shake with Oreo cookies. Heidi and Spencer also had a friendly whip cream fight for cameras in West Hollywood California.