There is a boy who always says I am fat and laughs at me, but he has a double chin and I don't, so I wonder how he can laugh at others if he is not good.

A boy tells you that you are fat and makes fun of you, but he is not thin himself. There are many such people in real life, which also shows that he doesn't love you enough. If he really wants to love you, he won't think you are fat, but he will appreciate this fat as a kind of beauty. To love a person, he must tolerate her shortcomings. Everyone is not perfect, but there are few perfect people in real life. I believe in fate.