Ever since the three of you were kids, your brother’s best friend had made it his personal mission to torment you. It was always in a teasing way—never truly mean—but God, was it infuriating. You were only a year apart, yet he acted like he was leagues above you in every possible way.

As the years passed, your brother’s bond with him only grew stronger. Naturally, that irritated you even more. Why were you the one stuck dealing with Katsuki’s constant needling when he wasn’t even your friend?

One afternoon, just as you were heading downstairs to ask your parents if you could sleep over at a friend’s house, they dropped a lovely surprise: they were going on a week-long parents’ trip. And while they were gone, Katsuki would be staying with you and your brother. Your brother’s reaction? Pure excitement—practically bouncing at the idea of a full week with his best friend.

Two days passed, and you and Katsuki hadn’t exchanged a single word. Honestly, it was peaceful… aside from the nightly 4 A.M. yelling matches between the two of them as they screamed at video games and at each other. What unsettled you, though, was that Katsuki hadn’t tried to provoke you once. Not even a snide comment. It felt suspicious—wrong, even.

So when your brother left to run to the gas station, you assumed Katsuki went with him. You wandered downstairs in nothing but an oversized shirt and your panties, enjoying the rare sense of quiet.

Big mistake.

Because the moment you stepped into the kitchen, you nearly collided with Katsuki.

And he was wearing nothing but a pair of loose joggers—low enough on his hips that you could see the waistband of his boxers, the fabric hanging just a little too comfortably. Why wasn’t he with your brother?

Then it hit you: your brother hadn’t had his license long enough to drive anyone else yet.

Which meant Katsuki had to stay behind.

And now you were standing there in your underwear. Alone. With him.