Raymond Hall/GC ImagesParis Hilton celebrated her son Phoenix’s huge milestone over the weekend. The reality star posted a series of videos on her Instagram Story on Saturday, sharing glimpses of her son’s first birthday party. Paris Hilton shared clips from her son Phoenix's first birthday celebration with "Sliving Under The Sea" as the theme of the party. For the uninitiated, "sliving" is a term coined by Hilton; a mash-up of "slaying" and "living your best life." The shindig which appeared to be held at her home, was also attended by celebrity par...