how do i get my husband to stand up to his mom??

Asked by not_my_main

ok so this has been going on for like 3 years now. his mom calls or texts him like 5 times a day, shows up at our house without asking, and last week she let herself in with the spare key while i was still in my pajamas on the couch lol. i asked him to talk to her about it and he just says "thats just how she is" or "its not a big deal, just ignore her." its a big deal to me!! i feel like a guest in my own house sometimes. he wont say no to her about anything, even when it messes up plans we already made. like we had dinner reservations for our anniversary and she called upset about something dumb and he left to go deal with it. i dont want to be the mean wife who hates his mom, i actually like her fine when its normal amounts. i just need him to actually set some kind of limit with her instead of always taking her side or just avoiding the conversation completely. how do you get a husband who avoids conflict with his mom to actually do something about it? has anyone dealt with this and it actually got better?