I would definitely talk about the money, but as a thing, without any emotions. Look together at what income you have, what expenses are required, give yourself each a little personal amount/allowance to spend as you each see fit and set an agreed upon limit where if one wants to spend that amount of extra money, they first have to talk to the other. If someone does not keep to the agreed upon rules (and maybe only make them for 3 months and then re-evaluate) then there should be agree upon consequences. With a plan you both have input on, one shouldn't need to get defensive or emotional later.

The problem I had is my husband made a lot more money than I did and would spend more money (but neither of us overspends or feels the other overspends). And, he was more conservative than I on how much money should be spent overall, both. But I realized my feelings were my own problem (since he was not overspending and did work and make more money) so I usually solved our disagreement by going and getting a/nother job to make as much as I needed for whatever "extra" I wanted. I am not a cheap date