Do you think he will be happy?

You are not being fair to yourself. You relationship with your ex is over. If he comes knocking at your door, don't open it. It's over. It's done. Get over it and start a new life. Just make sure that he understands that his responsibility to help support his daughter does not entitle him to "special favors" from you. You need to adopt the attitude that outside of child support, what he does is no concern of yours (unless it's illegal) and what you do is no concern of his (unless it's it's illegal).r