Dear nickita:
You read reasonable to me, sensible. I think expressing to him your unwillingness to be a second choice is an excellent idea.. because it is true to you. I imagine he wouldn’t want to be your second choice, to think that you are with him because your first choice is not available. So hopefully he will be empathetic and honest. At that point, better not bring up the topic and hopefully his behavior will be evidence that you are his number one choice.
You are welcome and hope to read from you again, anytime you will post, I will reply.
anita