feeling disappointed

My SO an I have been together it will be five years at the end of the month we have a 1 year old daughter together. There has always been plans to get married eventually. Not right away we couldn't afford it right away anyways. His parents have deicided to end there marrige this February and its has been non stop drama between his mom and dad. now he doesn't want to get married ever! Because it would be easier to separate without all the legal stuff wouldn't have to go through lawyers to deal with. Or so he thinks. We have a kid together an plan on more, chances are a lawyer would be needed if we split anyways.. I am just so disappointed and upset. his parents haven't had the best relationship they were only dateing for a month or so when she got pregnant with his sister. And they were married a couple of months later. And it's been a very rough 18 years for them. It hurts me to think that he doesn't want to get married because this way he won't have to waste money on lawyers. Feeling hurt and disappointed  and I don't think he realized it