Tik Tok sends a message to people who pay attention unilaterally.

If Tik Tok sends a private message, if you only pay attention to the other party unilaterally, you can only send three sentences. If the other party doesn't reply, you can't continue to send it. If the other party replies, you can continue to send it, and the other party can see what you sent. If two people care about each other and become friends, there is no limit to the number of private messages.