Scarlett Johansson and Colin Jost hosted a star-studded Christmas party Thursday night in New York City. Celebrity guests including Jon Hamm, Alec and Hilaria Baldwin, Chris Rock and more arrived around 9:00 p.m. and partied until the wee hours of the morning. Johansson and the “SNL” star made a stealthy exit at 4:00 a.m. after shutting down the bar. See the festivities below.