I've always been a firm believer that we have to handle
our own parents FIRST. In other words it is your girlfriends
JOB to handle
her Mother, not yours. She should tell mom, 'you're crossing the line here and you need to stop it'. I think you should have frank conversations with your girlfriend about her mother, then let her handle her mom, and discuss with girlfriend, what you are to do/say to her mother should she continue. It is very important that you both be on the same page/team where this (and anything else) is concerned. Now, if girlfriend won't, different story. But I would be very careful about what I say to mom-in-law-to-be without first going thru the scenerio with girlfriend. That old saying about 'I'm the only one that can kick my dog' holds true and fast, and you'll find that out the hard way if you don't fully discuss the possiblities (of a confrontation) first! Good luck! (and btw, i've been married 30 years, so brother i know of wense I speak!

)