The Family Stone (2005)

Everett Stone (Dermot Mulroney) wants to bring his girlfriend, Meredith Morton (Sarah Jessica Parker), to meet his bohemian Connecticut family at Christmas. Straitlaced Meredith, feeling she needs backup, asks her sister Julie (Claire Danes) to come along. Hoping to win the approval of her boyfriend's parents Sybil (Diane Keaton) and Kelly (Craig T. Nelson) and the rest of the family, instead Meredith succeeds only in highlighting her uptight personality and making Everett doubt his intentions.