We can’t get along with everyone in our lives; that’s just a fact that we have to deal with. At the same time, it doesn’t mean that we shouldn’t at least try.
Apparently, this thought hasn’t crossed the OP’s future MIL’s mind. She started their first-ever meeting with a relatively obscene question and when the woman’s answer didn’t please her, that’s when it all started rolling downhill. In the end, the situation got so bad that she decided to sacrifice her family heirloom just so her son wouldn’t marry his girlfriend.
More info: Reddit