The girl's answer in one sentence shows that he understands and is clear. Stop nagging.

Although it's just a word "Oh", it still has many meanings, which means that what you said is reasonable, and he will not argue any more, and will definitely do what you mean.

There is also perfunctory, you talk too much and annoy him. In order to avoid your nagging, answer, in order to perfunctory you, quickly end this didactic conversation, which will make him feel worse and worse, and feel that you are in charge too much.