National Lampoon's Christmas Vacation

It's Christmas time and Clark decides to invite all the family to have 'the most fun-filled old-fashioned family Christmas, that no one will ever forget.' When the first relatives arrive, Clark goes out on the roof to rig the lighting. The one thing that Clark wants is to surprise the whole family with is the installation of a pool, which he already ordered. Unfortunately, the bonus check Clark expects any minute is overdue. Tempers rise and not just because of the late check. Uninvited cousin Eddie arrives with his family in their mobile home.