tl;dr Trying to think of ways to avoid the legal portion of marriage style relationships. While still having the traditional relationship experiences.

I was thinking the other day about how to engage a lot of women who want the marriage commitment/experience, in a LTR that goes into the marriage setting(past 3 years, co-habitation, possible kids) and appeases the relatives. I was thinking about not legally getting married but having something very similar to a wedding(just without the legal part) to give her that show for the relatives she desires while still maintaining legal independence from her. I.E. (Avoid divorce rape) There is no common law marriage where I live, the only problem I'm having is if I ever decide I want a kid, I'm having a hard time thinking of a way to avoid being legally attached to her in any way at that point, aside from solo adopting, or working out a surrogacy agreement with someone... What ideas are there? Is my idea plausible? Are there people that currently do this or have tried something similar?