my thoughts are certainly not professional. Just very real to my heart as I have had the same struggles. when does the ultimatum really stand? You are right, if you never have fun, you will never be able to compete with a vacation in FL. He is just not ready to decide and is still discovering what he wants. Right now he ways he wants to take you to the concert. that is a good sign. You will have to decide what you cn or cannot do. there are things you will and will not do, but there are also things you can and cannot do. If you cannot go to the concert then tell him your hurt feelings that you would like to go but you just cannot due to his choices. If you can go then again tell him your mixed emotions about this. Tell him you really want to go but feel so uncomfortable with this dual relationship. Ask him what you think you should do. that might be a great insight to see what he is thinking. Men also like to solve problems.
keep listening to your heart and know that just because you go to the concert does not mean you accept the A or are willing to back down on other things. Just an opinion. proably not right, but my thoughts