When my 17-year-old sister ate cinnamon rolls meant for a cancer patient’s family, I thought my wife, Hannah, would just get over it. Instead, she changed our locks, filed a police report, and took my sister to court. I never saw the revenge coming.

I’m 36, and I’ve always been protective of my little sister Lily. She’s only 17, and with our parents working all the time, I’ve kind of filled that big brother role since she was small. My wife, Hannah, has always been understanding about this, even when it meant Lily spending a lot of time at our house.

Hannah is 34, and she’s genuinely one of the most patient people I’ve ever met. Calm, easygoing, the kind of person who’d rather keep the peace than start a fight. Which is why what happened next caught me completely off guard.

The problems started small, the way they always do. Lily had been coming over more often during summer break, sometimes bringing her friends to use our pool. At first, Hannah didn’t mind.

She’d even bring out snacks and drinks for the girls. But every single time they left, Hannah would find wet towels thrown all over the bathroom floor, sunscreen smeared on the outdoor furniture, and empty chip bags stuffed between couch cushions instead of thrown away. “Your sister and her friends treat this place like a hotel,” Hannah mentioned one evening while she picked up soggy towels for the third time that week.

I talked to Lily about it. “Hey, you guys need to clean up after yourselves when you’re here. Hannah’s not your maid.”

Lily rolled her eyes but nodded.

“Yeah, okay. Sorry.”

For a few weeks, things improved. The girls cleaned up better, and Hannah seemed more relaxed about having them over.Then Hannah started noticing things going missing. It began with small things, like a bottle of her expensive perfume that she’d just bought, a sweater she’d been looking for, and some makeup from her dresser. “Have you seen my new lipstick?” she asked me one morning.