Enjoying some quality time with her son Mason, Kourtney Kardashian was spotted out in New York City on Sunday (May 29).The “Keeping Up with the Kardashians” babe looked so proud as her little guy climbed some stairs all by himself while the paparazzi looked on.Kourtney recently told press that her newly-engaged sister Kim Kardashian has been nothing but real with her fiancé Kris Humphries.“Kim is totally herself in front of him. Everything is easy, comfortable, no stress. He fits in with the family already. I think they’re just themselves, and I think that’s the most important thing.”