In love with his one and only, Jim makes a proposal to Michelle. A happy couple sets a date and begins to seriously prepare for the wedding of their dreams. Stifler decided that he would be the best man of the groom, a freaky bachelor party with strippers in Jim's house, and at that time the parents of the bride and groom come to the house, who decided to get to know each other better at dinner.
Matured young people still fall into funny situations, as they did in school. Stifler and Finch arranged a competition for the possession of Michelle's younger sister, and Jim, deciding to have an intimate haircut, decorated them with a wedding cake. So the American wedding turned into a world of chaos and stupid accidents.