Your parents' views are, by current standards, out there. Getting in their faces about it would be needlessly disrespectful, but there's no reason for you to tiptoe through their delusional little terrarium as if you can't bend even one blade of grass.

If the guests want to wrest the check away from the host, because the host is also the guest of honor, then the guest who volunteers has to cover the whole thing. A guest can't volunteer -all- of the guests to pay for the host/honoree.

Separating is not divorcing. Please keep that in mind. It is, instead, the second step in seeing if there's a better way to manage your family.

A lot of support gets withheld out of fear of awkwardness and misspeaking.

You don't want someone who can't tell the difference between having a different opinion and dismissing your opinion.

Apparently you have ample proof from experience that you're not going to stop world evil by debating your in-laws into submission, so it's okay to choose not to try.

Instead of talking at each other about the non-business-related contact, talk to each other about your concerns about marriage. Listen a lot, too.