Now that I already have kids, I view marriage as optional, and only with a prenuptial agreement. Commitment happens in the heart. If for financial reasons getting married made sense, I would marry again. Or if my SO really wanted to. But it is not something that would be a deal breaker for me.

I don't regret having been married, and I still view my parents' marriage of 56+ years that ended when they both died within 3 months of each other to be an ideal. I do want someone to grow old with, but whether or not we are married won't be that big of a deal to me as long as our hearts are on the same page.