You are so kidding! Expensive vacation when neither of you is securely in work? He is irresponsible and immature, and I'm happy that you aren't being sucked in by this. When you look back on this from a few years time and your own life is stable, you will congratulate yourself that you read the signals and separated.

If he's this childish about a holiday, just imagine what he would be like in the for better or worse circumstances of a long-term partnership - if either of you became ill for example.