My sister kept walking around my husband in just a towel and called it a "test"—then one day, he did something that made her turn bright red.

When my younger sister Kayla called me crying after her boyfriend of six years threw her out, I didn't hesitate.

She had two suitcases, less than $300, and nowhere to go.

"Stay with us until you get back on your feet," I told her.

My husband, Andrew, agreed without hesitation.

For the first week, everything was fine.

Then Kayla started doing something that made me increasingly uneasy.

Every morning after showering, she'd walk from the bathroom through our kitchen wearing nothing but a towel, even when Andrew was seated there drinking coffee.

The first time, I ignored it.

The second time, I quietly pulled her aside.

"Kayla, could you please put on a robe before coming downstairs?

Andrew's usually here."

She laughed.

"He's your husband, not a teenage boy."

"I know.

I'm asking because it makes me uncomfortable."

"Fine."

Except she didn't stop.

If anything, it got worse.

She'd stand at the kitchen counter making coffee in that towel, chatting with Andrew as though she were fully dressed.

Once, she even asked him to reach something from a high cabinet while I stood three feet away.

Andrew looked uncomfortable and immediately stepped out of the room.

That night, I confronted her again.

"Kayla, I've asked you twice."

She rolled her eyes.

"Why are you acting so insecure?"

"I'm not insecure.

It's my house, and I'm asking you to respect one boundary."

Then she actually laughed.

"Honestly?

Think of it as a test."

"A test?"

"If Andrew can be tempted just because another woman walks past him in a towel, wouldn't you rather know?

If he fails, that's on him."

I just stared at her.

I'd opened my home to her when she had nowhere else to sleep, bought groceries for her, let her use my car for interviews—and somehow she had turned disrespecting me into a favor.

When I told Andrew what she'd said, his jaw tightened.

But he only replied, "I'll stay out of it.

She's your sister."

For three more days, Kayla continued.

Then Sunday morning, she came downstairs in that towel again.

I opened my mouth to say something.

Andrew touched my arm and whispered, "Don't.

It's my turn.

I'm going to teach her a lesson she'll never forget."

I looked at him.

For once, he didn't leave the room.

He calmly set down his coffee and looked at Kayla.