Regret

That was what Chibiusa felt. The other day, she was so jealous of you that she wanted to hurt you emotionally and physically. So, she did the unthinkable.

While you, your boyfriend, and Chibiusa were at the park, you went to get some snacks. Chibiusa was constantly flirting and touching your boyfriend, and he looked straight up uncomfortable..

As soon as you came back, she had the audacity to kiss him in front of you while your boyfriend was trying to push her away for two reasons: One, he was with you. And two, he didn't feel the same way about her. You were upset with her because of it.

She realized how she basically destroyed your relationship because of her selfishness and jealousy.

She was now at your front door, slowly knocking on it.