We met many similar situations when we were in college. Boys bring a lot of food. For example, a person invites a classmate to eat in the canteen, but the classmate is playing a game or doesn't want to go, so let him help with the meal. At first, people will help him bring food. Later, you found out that the classmate was always like this, so you stopped bringing him food.

But I think returning books is different from eating. You're not going to the library. It's normal for you to ask her to return your book. Just like eating, you have to eat, but you don't want to go. People ask you to go with them, but you ask others to bring them to you. It will be bad for a long time.

Very few girls are generous and selfless. It's not your fault. In a word, "if others don't treat you as a true friend, you don't have to worry about her." Remember, girls who play well together are not necessarily true friends. There are many such situations in universities. Adversity is the only way to see the truth clearly. This is the eternal truth.