esqueelio,
i agree with the others. You are an adult and you don't have to tell the whole story as to why you did it. Just let him know that you changed it for your own personal reasons and leave it at that. If he continues to push the idea just let him know that at this point you are not ready to share that reason with him.
I wish you luck with this...Lord knows we don't need anymore stress in our lives!!
Snow