AITA for insisting on checking my BIL’s girlfriend’s bags after she twice brought dairy into our home and sent me to the ER?

I have a life-threatening dairy allergy, and after my BIL’s girlfriend ignored the rules twice — once sending me to the ER — I said she could only stay with us if we checked her bags for dairy. Now the family says I’m treating her like a criminal.

I’ve had a severe dairy allergy all my life — hives, trouble breathing, epipens, ER trips, the whole thing. My fiancé’s family has always been respectful and careful about it, and when we moved in together, we established a zero-dairy rule in our home. No dairy products can enter the house, ever. Cross-contamination alone can hospitalize me. My BIL started dating his girlfriend about a year and a half ago. Before her first visit, my fiancé explained my allergy and the rule. Two days in, she bought dairy and cooked herself lunch while we were out. I ended up in the ER from cross-contamination. She apologized and said she “didn’t understand” how serious it was. We let it go for the sake of my BIL.

I’m the person with a life-threatening allergy, and after two ER-level breaches, I said she can only stay if we check her bags — or she can stay in a hotel instead.

Before their second visit nine months ago, we had a video call specifically to re-explain the severity of my allergy. But during the trip, I found candy wrappers and an empty milkshake container in the guest room trash. She had again brought dairy into our home — secretly — after witnessing my severe reaction the first time. My fiancé confronted her, BIL threw out every dairy item she had brought, and she was kicked out while BIL stayed. They stayed together afterward, but since then my BIL visits alone because I don’t trust her in my house for obvious reasons.

"She saw me go to the ER the first time — and she still hid dairy in my house."

Now BIL wants to visit again and she wants to come. We originally said no. But because we want to support BIL, we offered a compromise: she can stay with us **only if we check her bags every time she returns to the house**. If she doesn’t like it, she’s welcome to stay in a hotel or skip the trip. Suddenly we’re being called cruel and controlling, and accused of “treating her like a criminal.” All because we won’t risk another ER visit over something she has repeatedly done.

"If she wants the privilege of staying in our home, she has to respect the rule that keeps me alive."

I don’t think the request is unreasonable given the history. But now people are saying I’m the AH for invading her privacy. I’m not trying to control her — I’m trying to stay alive.

🏠 The Aftermath

Right now, BIL is caught in the middle. He wants his girlfriend included, but he also knows she caused two major breaches of trust — and one ER trip. My fiancé is fully on my side, insisting that we can’t risk my safety. The compromise stands: she agrees to bag checks or she stays elsewhere. The fallout? Accusations of unfairness, overreacting, and policing her. But no one seems to acknowledge that she repeatedly endangered my life despite clear communication and second chances.

The practical consequence is that we’re likely hosting BIL alone again, unless she accepts the boundary. The emotional consequence is the realization that some people think her “privacy” outweighs my physical safety.

I’m hurt that we’re being painted as unreasonable when all we’re asking is compliance with a rule she already broke — twice — after seeing the severity of the consequences.

"This isn’t about trust issues — she proved she can't be trusted with my health and my home."

The goal isn’t punishment. It’s survival. Her discomfort is optional; my allergy is not.

💭 Emotional Reflection

At its core, this isn’t about privacy — it’s about trust, safety, and respecting medical boundaries. You extended compassion the first time. You extended structure the second time. Now you’re extending a clear condition: she can be part of the household only if she doesn’t endanger you again.

Some people confuse boundaries with punishment. But boundaries are about protection. She ignored your health needs twice, knowingly, after seeing the consequences. Your feelings are valid, your fear is justified, and your boundary is reasonable.

Ultimately, she’s not being treated like a criminal — she’s being treated like someone who has repeatedly broken a serious house rule and endangered your life. Her comfort is negotiable. Your survival is not.

Here’s how the community might see it:

“This is a medical boundary, not a moral one. If she can't follow the rule, she can't stay in the house.”

“Checking bags is a mild consequence compared to sending someone to the ER. She already proved the risk is real.”

“If she wants privacy, she can stay in a hotel. She doesn’t get to have privacy AND violate medical rules.”

Most reactions would strongly support your boundary as reasonable, necessary, and proportional to the danger she created — twice.

🌱 Final Thoughts

You’re not demanding anything extreme — you’re demanding not to be hospitalized again because of someone else’s choices. That’s not controlling. That’s survival.

Whether she chooses to stay in your home or a hotel, the boundary is clear: your life comes first, and the people around you must act like it.

What do you think?
Would you insist on bag checks too, or refuse entirely to let her stay? Share your thoughts below 👇