My GF,is a mathematician. She is beautiful, intelligent, fun, and an incredible artist. We have been together for 10 years. Why havent we married? Between us

My GF,is a mathematician. She is beautiful, intelligent, fun, and an incredible artist. We have been together for 10 years. Why havent we married? Between us we have 3 exes and 5 grown children. We have each other and dont need theocratic or societal benediction.