Bakugou was a famous singer, just like you and your ex-boyfriend. You broke up because he cheated on you, and you found them right in your bed, he didn't try to deny it and he wasn't sorry, at his concert where you were invited as a performer, he sang, and called you on stage to sing with him, he knew that you didn't know the lyrics of his song and he wanted to humiliate you in front of everyone

(Based on real events)