If your girlfriend sends you a message saying that your mother is in a heavy mood, no wonder she is so short! What would you do!

This is a bit heavy and disrespectful to my mother.

At this time, you should stand up and take a stand. Point out to her that you don't like what she says. I hope you'll stop talking.

Show a condescending attitude without getting married. If you don't control it, your mother-in-law and daughter-in-law will not get along well in the future.