DEAR SOMEONE ELSE’S MOM: I can’t believe how my girlfriend puts up with the nutjob she shares her apartment with.

This woman will corner you and talk for hours about her insane conspiracy theories. At least they change up from time to time. Her latest started getting bad when King Charles got crowned. She is totally and completely convinced he had Princess Diana murdered so he could marry Camilla. I was a little kid when she died, and I remember it because when my mother heard Princess Diana wasn’t wearing a seatbelt she started using that as a way to make sure we all strapped in so we didn’t die like Princess Diana.

I am getting to the point where I don’t want to hang around my girlfriend’s place. That makes it harder for us to spend time together because I live in an even more complicated living situation.

How do I get this woman to stop running her mouth about things she knows absolutely nothing about? --- MAKE HER STOP

DEAR MAKE HER STOP: I know generally perfectly rational people who embrace their own perception of reality on certain topics. There’s the case of the bright, articulate young man, for instance, who would bet his life’s savings on the moon landing being a hoax.

Often little can be done to make a true believer doubt their faith. Perhaps, though, you might try beating the roommate at her own game as a way to temporarily shut down the rants by introducing subjects that she has no knowledge of, allowing you to have a turn at monopolizing the conversation the same way she does.

If the tactic works, she may grow tired of your tirades and find other ways to spend her time when you’re visiting your girlfriend’s apartment.

DEAR SOMEONE ELSE’S MOM: My husband grew up in a military family. Both his mom and dad were active duty until right before he started college. Because they moved every two to three years for the whole time he was growing up, he developed the habit of “traveling light,” as my father-in-law calls it.

I agree it’s good to not let our home get cluttered, but in my husband’s mind, if it isn’t used within a couple months of when we buy or are given something, then we don’t need it and out it goes.

He is always throwing things away that he feels we don’t need, without asking me if I agree. I believe this is how his parents treated him and his older brother when they were growing up, this idea of making executive decisions for other people.

That may have made sense when their parents were trying to keep their highly mobile lives organized, but we’re not moving anywhere anytime soon, and I have had to replace things he’s tossed because we do in point of fact need them, just not all the time.

I sometimes think he forgets that his parents, both officers, made enough money to go ahead and regularly replace things they left behind. We do not in any way have that kind of a budget.

How do I get my husband to understand sometimes you have something on hand for when it’s needed, and not just for everyday, all the time use? --- NEED A FEW EXTRA THINGS

DEAR NEED A FEW EXTRA THINGS: Like you, I have items around the house that get used infrequently, but do come in handy when I need them.

The danger of that kind of thinking is it’s easy to shove something to the back of a closet or cabinet and forget about it.

Perhaps you and your husband could come up with a mutually-agreed upon system of compromising on what stays and what goes. I’m thinking along the lines of working together for a quarterly, semi-annual, or other regularly scheduled review of what you’ve got on hand.

Because he’s possibly unaware of your thoughts on items he sees as being of no value, ensuring you’re part of the decision-making process not only reminds him he’s got someone else with a stake in household decisions, but it also gives you the chance to justify your rationale in holding onto some things.

By the way, hopefully rather than tossing everything in the trash, you and your husband are donating the stuff in good, usable condition to a local thrift shop or community service organization.

DEAR SOMEONE ELSE’S MOM: My big sister, “Jasmine,” has been a control freak all her life. We shared a room until she moved out when her job went fulltime and she could afford an apartment. It was her who was the one who told me what to do more than our parents ever did, and I admit to being a little intimidated by her when we were kids.

Last month Jasmine moved in with me and my boyfriend into our house because she lost her job when her company had to cut back. They gave her a good severance, so she is just now starting to look for new work, which means she has been around our house fulltime for the last few weeks, and has spent most of that time telling me how to run my house and take care of my baby, and even tried to rearrange my kitchen and pantry. Fortunately, my boyfriend is not as intimidated by her and pushes back when she gets to be too much.

I know Jasmine isn’t a bad person, but just one who feels the need to be in charge. She is helping out financially too because she is paying rent, which helps makes up for my lost income that happened when I stopped working to be home with our daughter for a few months before I will go back to working at least parttime.

I don’t want to seem ungrateful to my own sister, and I know it’s a good thing my boyfriend stands up to her, but do you think I should just let him do the telling her off so she and I can keep the peace? --- THE LITTLE SISTER

DEAR THE LITTLE SISTER: No, I don’t think it’s all on your boyfriend to stand up to your sister. It’s your house too, and she is a guest, albeit a paying one.

Next time she attempts to exert control, it may be helpful for you to thank her for her suggestions, but remind her you intend to run your own home the way you want it run.

There’s no need for you and your boyfriend to gang up on her, but I do believe your pushback will be more successful if both of you are firm and consistent in letting her know you’re in charge of your own home.