If money means security to you, and pleasure to your spouse, then you are going to be a saver and your spouse will want to spend. Such differences can cause huge conflicts. Communication and compromise are the keys, and when you talk, it's important to do it at a time when emotions aren't running high.
If you have children, and they're old enough to understand, consider bringing them into the discussion as well—not to the point of scaring them, but to let them know what's going on. Helping them to understand the principles of money management early in their lives could be doing them a big favor.