How annoying is it when a new person comes into the family and acts like they know everything!

Imagine helping a family member make a decision. You put a lot of time, thought and consideration into helping them. Then you find out the new family member talked to them about the same decision and talked them into deciding on something else, something you knew was a waste of money.

In this story, a young woman is in that situation with her mother-in-law and her sister-in-law’s boyfriend. It may be a small issue, but she feels like he was incredibly rude.

Check out the full story.

AITAH for not letting it go when my sister-in-law’s bf told me “Let’s get one thing clear, I don’t need to justify my actions to you.”?

This situation happened back in May of 2025.

Me (21 F) had been with my fiancé (25 M) for about 3 years when this situation occurred.

I genuinely felt like I had created good relationships with his immediate family (his mom, his dad, his sister (26), etc.

She had always been a nice addition to the family…

I am someone who each of these people have heavily relied on to help with doing their taxes, keep their car insurances up to date, help with school assignments (both the mom and sister were in school), etc. I never said no to any request or need.

The time came that my fiancé and I were going to move states for our jobs. When we were about to move, my sister in law (26 F) introduced us to her new boyfriend of 1 week at the time, a male (40 M).

The age gap worried me for the reason that my parents had an identical age gap and it is precisely what tore them apart over time. But I kept that opinion to myself and supported their relationship.

When we met him, I liked the guy. Thought he had a good sense of humor and seemed nice.

What happened next changed everything…

Around 4 months later I was shocked when things went sideways.

My mother-in-law had asked me to help her find a new laptop. So I facetimed her and we talked for around an hour going over pricing and options. Finally we settled on the 2025 Macbook Air (M4).

She was only going to use it for browsing, notes, and light schoolwork so I recommended the one with standard storage and RAM. This would save her close to $500 on a computer she is already paying $1000 for. Especially because I share 2TB of iCloud storage with her that I personally pay for. So we went with that option and I ordered it.

She had no idea why he did that!

A few days later she is talking on the phone with my fiancé when she asks him to pass the phone for her to tell me something.

She tells me that my sister-in-laws boyfriend said the laptop I picked was an older 2024 model (which isn’t true).

Based on that, he canceled the order I had placed and took her to buy a different one, which ended up being essentially the same laptop, just with more RAM and storage, so she spent more money for no real reason.

This would be frustrating.

I wasn’t initially angry but more annoyed because I had done the work and spent the time with my mother-in-law to arrive at that choice.

Also, he said he canceled it because it was an old model however I had the order confirmation with Model # to prove that wasn’t the case.

So to me, it was a big misunderstanding that led to my mother in law paying $1500 for the computer instead of $1000. However, she got more RAM and storage that she won’t need.

She knew what the mother-in-law needed!

On her technological ability, she will probably only use about 10% of the computers capabilities in the first place so the extra money felt wasteful. And she is not rich!

So, I decided since he is someone in the family I would reach out to him in a text to let him know there must have been a misunderstanding because the one I ordered is the same one he took her to get, and to ask that in the future if its something that I already helped with to please reach out to me so we can chat to avoid misunderstandings.

He responded with some computer specs and I just responded with proof that what I ordered was correct.

This is INSANE!

Once I sent the proof he responded with, “Let’s get one thing clear, I don’t need to justify my actions to you. If you have a problem with the decision, take it up with (mother in law).”

My jaw hit the floor. I was not expecting that type of reply and honestly felt disrespected.

I replied saying that I had come to him with a respectful tone so I would like the same back from him and even clarified that I was not asking him to justify anything. Just wanted to avoid future misunderstandings.

He left that message on delivered. And refused to address it.

WHAT? That sounds so dramatic!

Why wouldn’t he be kinder to a young woman making efforts for her mother-in-law?

Let’s find out how the Reddit community responded to this one.

This user has great advice for this woman!

That’s right! This user knows the MIL is at fault here.

This user suggests ignoring these situations.

If you enjoyed this story, check out this post about a mom who can’t figure out why her babysitter quit after what she thought was a routine question.

This user suggests letting the guy take the lead and see where it goes.

This user knows exactly how to treat this guy!

Somebody needs to maintain some distance here!