Keeping personal space tidy is a challenge in a house full of chaotic brothers, especially as the only girl in the family.

After her tiny room was constantly invaded, one sibling took home security into her own hands — with a sharp lesson that left everyone watching where they sit a little more carefully.

You’ll want to read on for this one!

I grew up, only girl with 7 teenage boys.

So, I lived in a two-story family house in my early teens.

We lived downstairs — my mom, my stepdad, and three older brothers.

Upstairs, there were two parents with four boys too, so there was a lot of testosterone in the air, to be frank.

She had a hard time carving out space for herself, so needless to say, she took caring for personal space very seriously.

We lived by sharing rooms.

The boys shared two rooms, and I was stuck in the middle with a very, very small space — 5 or 6 square meters.

While their rooms looked and smelled awful, I made sure to keep my small, personal space very neat and tidy.

I also invested in a full TV setup with a quite large TV (mid to late ’90s).

But her brothers didn’t share this same respect.

I found out that if I was away, my brothers would use my room to be gross in — as if the rest of the house wasn’t enough. 😅

It seemed there were no lines they wouldn’t cross!

They would use my bed, my TV, and my VHS and just lay there being disgusting.

So, one day, I found out that they would also use my room to bring a girl once in a while.

So she decided it was time to to take matters into her own hands.

Flash forward to me, on my knees, making my bed with a thin bedsheet and about 250 flat-headed push pins underneath it.

I covered the entire 90×200 mattress.

Then, I left for school.

Later the next day, I got a call from my mom.

Turns out, it didn’t take her brothers long at all to fall into her trap.

She had a very hard time trying not to laugh too much while telling me that my one brother had been working hard to get with this girl from school.

She knew he wasn’t a good guy, but she gave him a shot.

That shot was in my room, on my bed. On a needle mattress.

This little trap worked like a CHARM.

No human was harmed, but no one ever used my room after that.

My brother says, 25 years later, that he still checks his chairs and other furniture — just to make sure there are no needles. 😇

Looks like it only took one painful reminder to keep her brothers out of her room for good!

What did Reddit think?

If anyone should be allowed a room with a lock, it’s her!

Her brother’s behavior is low, even for a high schooler!

This commenter finds the story quite empowering!

Looks like this sister isn’t the only one to think of using tacks for revenge.

The brother got a shot with the girl, but the real sting came from the mattress.

Looks like her brothers finally got the point — literally!

If you liked that post, check out this post about a rude customer who got exactly what they wanted in their pizza.