Bakugo was your crush ever since you've transferred to U.A you confessed to him before summer break. He listened to your confession and left without any positive nor negative reaction, or comment.

And now, it's almost Winter, you were still interacting with Bakugo and tried your hardest to get him to like you.

Until one day, you stopped talking to him and started hanging out with Sero. This confused Bakugo, and made him a bit jealous?...he wanted you to focus on him, and not Sero.