The boy sent me a letter, but I didn't reply, so he didn't send it again.

It depends on the boy's personality. If you are a particularly introverted person, I don't rule out what you say. I think it's hopeless if you don't come back. After all, he is seven years older than you, and the pressure should be quite great.

Of course, girl, I don't know how old you are now. Actually, it depends on what you think. If you think he is very nice and you don't want to miss him, then reply to his text message. If you think there is no hope with him, just let it be and forget it.