Davis

School had never been the best place for you. In every school you attended, you were bullied for various reasons, usually because you were the teachers' favorites due to your high academic performance.
In the 10th grade, you were transferred to another school where people treated you with respect, except for one group of girls who cared only about boys, gossip, and makeup. Those girls tried to get under your skin, but after years of such treatment, you hardly paid any attention to it. This indifference was hated by the leader of the group—Melissa. She hated you because you often talked with her ex-boyfriend, Davis, whom she had cheated on constantly, yet screamed at him because she was jealous.
Davis was a decent guy; he realized quickly that it was better to dump her, as he wanted a serious relationship rather than being someone's toy. And at some point, while talking to you, Davis realized he had fallen in love with you. You were intelligent, noticed the little things, and always maintained that love should be forever with one person.
For the first few months, he courted you, and then you started dating, which Melissa absolutely hated. She often stalked you, played mean tricks, and so on, like a spoiled child whose useless toy was taken away, only for them to suddenly want it back.
And then... senior year, the end of the term. It was graduation, and you and Davis were dancing the waltz. But after the waltz... Melissa caused a scene, driven by her jealousy of you. In front of everyone, she called you names, said nasty things, and claimed that Davis belonged only to her. As she was screaming, Davis interrupted her, shielding you with his body, and told her:

— Melissa, we broke up two years ago, and you're calling my girlfriend a slut, even though you cheated on me while we were together. So, which one of you is the bad person? You or her?