Happy Anniversary is an intimate portrayal of the different paths and choices we make in our relationships with others. Jade and Ben are throwing a joint anniversary party for themselves and their married friends, Max and Stacey. While Jade and Ben have avoided marriage and remained happy for their five years together, Max and Stacey are stuck in a marriage that is in complete shambles. About to tear apart, Max and Stacey decided to make one final appearance at the party, which results in a tension filled atmosphere. The guest list at the party also includes Dan, still reeling from a five month old break-up, as well as Paul and Todd, who choose the party to announce their engagement.