What do you mean he didn't reply after sending a confession message to a girl?

The objective reason is that maybe she can't reply to your message in time because of something. The subjective reason is that she needs time to think about this question and whether to answer you or not. Because a girl is still very demanding about love, she won't just be with someone casually, and she will definitely think about her happiness. But don't be impatient and wait patiently. If she hasn't answered, you'd better meet her and ask her directly, so as to solve the problem face to face. I wish the landlord can hold the beauty back smoothly!