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I HEART U
A few weeks later (Dec. 24) at the Kardashian annual holiday party in L.A., Kim steals a balloon-sealed kiss from her youngest family member. "He really loves me; I already know it," Kardashian told PEOPLE in 2010. "I take pictures of him all day and we have a really special bond. I know I'm his favorite aunt."
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Très chic! Kim and Mason chill poolside in matching navy nautical get-ups during a family vacation in the Dominican Republic on March 30, 2012.
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Kim proves she's more than ready for motherhood by keeping a close eye (and hand!) on her nephew while visiting a Malibu park May 6. "Being a mom is something I've always wanted," shared the reality star.
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ALL IN THE FAMILY
During a July 8 hospital visit, Kim and Mason beam at the newest addition to the Kardashian clan – Kourtney's daughter Penelope.
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On Aug. 8, Kim gives her big sister a much-needed break and takes Mason out for lunch and a little shopping in Calabasas, Calif. "I know Mason is going to be the best big brother in the whole world."
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"Love you Mase," wrote Kim after posting this adorable shot of her and Mason playing around with straws.
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While heading out to church with his "favorite aunt" in Agoura Hills, Calif., on Aug. 26, Mason keeps an eye out for any bad guys – or paparazzi!
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Two and a half months before announcing her big pregnancy news, the reality starlet gets in a little pre-baby practice by taking her cutie-pie nephew to the Miami Children's Museum on Oct. 3.