My mother-in-law, Diane, has a strange habit of going into our bedroom whenever she visits. She always denies snooping, claiming she just “wandered in by mistake.” At first, I tried to overlook it. She would step out of our room with that guilty look on her face, insisting she had only been looking for the bathroom. But her curious behavior became more frequent, and I started feeling uneasy. My husband, Mark, told me I was reading too much into it. He said maybe his mom just liked to see how we decorated. But I had a different feeling.

Over time, I noticed small clues that someone had been in our room. Sometimes, dresser drawers were slightly open, or items on our nightstand were moved. One time, my jewelry box was in a different position. Though nothing was missing, it still made me feel my privacy was being invaded. It created tension between me and Mark because he didn’t want to confront his mother.

This past holiday season, we invited Mark’s parents over for dinner. We planned a big meal with turkey, mashed potatoes, and a homemade apple pie for dessert. Mark was excited to spend quality time with his parents, and I was determined to be a good hostess despite my concerns about Diane’s snooping.

Before they arrived, I realized we couldn’t find the key to lock our bedroom door. Usually, that was my solution—lock the door, problem solved. But now, with the key lost, I needed a different approach. I decided to protect our room in a less obvious, more playful way. Maybe a small trick would deter Diane from poking around. I didn’t want to be mean, but I also wanted to send a message: our bedroom was off-limits.

I rummaged through some old boxes in the attic, searching for something that could serve as a harmless little trap. That’s when I found a motion-activated air horn I had bought as a gag gift years ago. It was basically a small horn that would blow loudly if someone moved in front of the sensor. Perfect, I thought. It wouldn’t hurt anyone, but it would certainly give a scare. I tested the device in my office by waving my hand in front of it. It let out a loud “BWWWAAA!” that nearly shook the walls. My heart pounded, but I smiled, thinking it would definitely surprise any snoop.

I carefully placed the horn on a shelf inside our bedroom, facing the doorway. Then I draped a piece of dark cloth around it so it wouldn’t be immediately visible. My goal was not to embarrass Diane in front of everyone, but to discourage her from entering the room without permission. I truly hoped she would stay out, and that the horn wouldn’t even go off.

Soon enough, Mark’s parents arrived. Diane wore a festive sweater with Santa Claus patterns, and my father-in-law, Frank, carried a bottle of wine. We all greeted each other warmly. I did my best to push my worries aside, focusing on making sure the dinner went smoothly. We chatted about holiday traditions and the cold winter weather. The kitchen smelled of turkey and spices, making me feel cozy despite my underlying stress.

Dinner was served in the dining room, which was decorated with red and green candles and a simple wreath on the table. Everyone enjoyed the food, and the conversation flowed nicely. Diane complimented my cooking, and Frank told some jokes about holiday shopping nightmares. For a moment, I felt grateful and happy to be surrounded by family. I tried to believe maybe Diane wouldn’t snoop this time. Maybe my concerns were all in my head.

We were halfway through dessert when it happened. A sharp, piercing scream echoed from the direction of our bedroom. I froze, my fork halfway to my mouth. Mark whipped his head toward the hall, and Frank nearly dropped his wine glass. Then I heard the unmistakable blare of the air horn: “BWWWAAA! BWWWAAA!”

Diane stumbled back into the dining room, looking disheveled and wide-eyed. She kept one hand pressed against her chest. “There—there’s something in your bedroom!” she shouted, her voice shaky and frantic. My father-in-law stood up and rushed over to steady her, while Mark jumped from his chair, asking what was wrong.

I got up calmly, my heart pounding but my face composed. I knew exactly what had happened. We all hurried into the hallway, where we could still hear the echoing noise from behind the bedroom door. Carefully, I pushed the door open a crack. The motion-activated horn detected movement again, screaming its loud blast. I switched it off, then retrieved it from the shelf. Diane stared at the device, clearly realizing it was just a prank.

She pointed a trembling finger at me. “What on earth is that thing?” she demanded. “I nearly had a heart attack! What kind of joke is this?” I took a deep breath, feeling the tension in the air. My voice came out more defensively than I intended. “I’m sorry you were scared. But we’ve asked you not to go into our bedroom so many times, and you always deny it. Since we lost our key, I placed this horn to stop anyone from sneaking in.”

Mark frowned. “Honey, you went that far?” He looked conflicted, caught between his loyalty to me and his concern for his mother. Diane glared at me, still shaken. “I was only looking for a place to put my coat!” she claimed, though she had already hung her coat on the rack in the hallway earlier.

My father-in-law seemed both worried and annoyed. “Diane, maybe we should calm down,” he said gently. But Diane looked furious and humiliated. She grabbed her purse, muttered something under her breath, and walked straight out of our house. Frank apologized quickly, then followed her outside.

Mark and I stood there in the hallway, the air horn still clutched in my hands, the smell of apple pie drifting from the dining room. My face felt hot, and I wondered if I had gone too far. Sure, Diane had invaded our privacy time and time again, but had I done the right thing by scaring her like this? Mark didn’t say much. He just sighed and walked back to the table, leaving me alone with my thoughts.

Eventually, he and I discussed it. I explained how important our privacy was to me and how her constant snooping had made me feel unsafe in my own home. Mark admitted he had ignored the problem for too long and understood why I did what I did. However, he was worried that the holiday dinner ended in a big fight. We both felt sad that things had gone so wrong.

Since that night, Diane hasn’t visited. She’s still angry, and Mark has tried talking to her on the phone with little success. Part of me feels relieved to have our space back, but another part is hurt that the family situation turned so sour. I know my approach was dramatic, but so was her refusal to respect our boundaries.

So, here is my question: if you were in my position, would you have handled your mother-in-law’s snooping the same way, or do you think I went too far by setting up that air horn trap?