ok the girl is crazy, so I have 3 theories for this:
1) simple, she is crazy and in the next chapter, there will be a troll.
2) well she knows ooki and does that so that he has a chance with her.
3) I don't think ooki doesn't know that something happened so maybe he will do something like with the delinquent girl.
They try to throw him a bone, and it ends up whacking him upside the head for no fault of his own. It's like something Kafka would write.
His one fault is his lust, and even then he's not hurting anyone, really. Yet every girl around him wants to manipulate, use, abuse, or harm him, if not snatch away his harem.