@TravellingSpoon
YANBU of course. Couples don't have to be joined at the hip. However, I would never go on an actual holiday without my DH though. (And he never would without me.) Maybe a day trip, but not a week or two away (and not abroad.) Doesn't mean others can't/shouldn't, but it's not for us.
Don't cave. I agree with @TheWernethWife that he IS being a bit controlling. And people trying to shut that point down can just be quiet, because wernethwife DOES have a point. Anyone reading the OP's posts who can't see her DH is being somewhat controlling needs to give their head a wobble. Of COURSE he is.
Also wonder (like a pp) if he is able to afford solo trips to Asia and Australia, how come YOU have had to save yourself out of your low wage for YOUR trip?
Do you not pool finances?
He is trying to piggyback on your trip, and manipulate you into letting him come along. I bet he won't allow you on HIS trip. If he DID, he would probably want you to pay your own way.....
Also, why does he want to go on a Religious trip if he is a non-believer?
As a few others have said, separate finances, and solo trips, sounds very weird (to me) for a married couple. This isn't the first time I have read a thread like this over this past day or two. Some couples seem to lead separate lives.
It concerns me that it's often the higher earner who is making sure it stays this way, and it's usually the MAN (obviously so he doesn't have to share HIS money.)