Two people with such opposing methods of living your lives shouldn't get along as well as you two do! But you do get along. In fact, each of you derives a lot of benefits from the other's way of doing things.
If there's any tension that's generated by your differences, it should be a creative tension that actually furthers your purposes. You bring your spontaneous, high-flying creativity to the table and your partner brings their sensible, levelheaded approach to any problem, and you blend your strengths into one. You are actually a really good influence on them in this regard; they tend to get a little too worked up at times about security and making plans, but you're able to jostle them out of this rigidity with your spontaneity and enthusiasm for life. You show them that it's okay to take risks from time to time. In return, they ground your sometimes off-the-wall ideas. They help you to see what's a good, calculated risk and what's just way too risky.