I have written about this before, but my husband was similar. He felt that we were being responsible with our money just by not being in debt and saving a bit, and felt that following a budget would be very constraining. I got him on board by talking about our feelings associated with money, what we valued, how to align our spending with what makes us happiest, and our long term hopes/dreams and how having a nest egg/FU money/financial freedom would facilitate those. It helped that our parents have both gone through different money issues in the past, which allowed us to talk about what we want to do differently. His parents happened to be at a point where they wanted to do something else with their lives but couldn't quit their jobs because of a lack of savings (despite having made $250K/yr for the last 10 years - but hey, spending $1200 a month on groceries for 2 people will do that).
Those conversations got him on board with following a budget (we use YNAB to track spending), and what he thought would be constraining has actually made him feel more secure, because he knows where we are financially at all times (I've heard him extolling the virtues of YNAB to other people). He is still more spendy than me, and will probably always work, but that is fine because he has changed his behavior where it really matters for me (upping our savings rate, buying a smaller/cheaper house, etc.). And hopefully he feels I've tried to change to accommodate his needs.
So my advice is: don't talk about money. Talk about the feelings associated with money, and accept that your feelings are likely to be different, but that you can still find common ground.