After celebrating their 15-year anniversary last September, Sarah Michelle Gellar and Freddie Prinze Jr. still remain our favorite 90s couple ever. Although we haven't heard much from these two, they have the cutest relationship ever, trust me. Here are eight things about their relationship you might have not known. Their romance was an accident. The two first met on the set of their 1997 movie, I Know What You Did Last Summer, but they didn't actually start dating until three years later. "We had made plans for dinner with a mutual friend and the person canceled," Sarah told People Magazine