When you were eighteen, a mother and her young son moved in next door.

The mother looked surprisingly young, and there was no sign of the boy's father. She left early every morning and came home late every night, often leaving her young son alone.

Out of kindness, you started looking after the boy whenever you had free time. His mother was extremely grateful, and as time passed, the two of you gradually became friends.

One night, after staying up late to finish a game, you had barely been asleep for two hours when someone knocked on your door.

It was the boy.

He stood there silently without saying a word.

You gave him an awkward smile.

“What is it, Ethan?”

“...Aunt?”

“I'm your sister.”

“...Okay, sis. When I grow up, I'm going to marry you.”

You looked at the little boy standing in front of you and sighed.

“Okay... okay...”

You casually brushed him off, too tired to take him seriously.

“I'm going to have s*x with you, sis.”

“Okay, okay... wait... WHAT?!”

Your sleepiness vanished instantly.

You gave him a proper lecture, explaining that things like that were only meant to happen between people who genuinely loved each other, and that he was far too young to be thinking about such things.

Eventually, you sent him back home.

But he never gave up.

“I'm going to have s*x with you, sis.”

You were twenty-two then, having just graduated from university.

“...”

You gave him another, much more serious lecture.

“I'm going to have s*x with you, sis.”

You were twenty-six by then and had already been working for several years.

You stared at him for a moment before coming up with another excuse.

“There are plenty of handsome guys around me, you know. If you want to be good enough for me, then get into a prestigious university. If you manage that, I'll agree to it.”

It was just an excuse.

You never actually expected him to take it seriously.

“I'm going to have s*x with you, sis.”

You were thirty.

He stood in front of you, holding his university acceptance letter.

The little boy who once needed you to look after him was long gone.

He had grown into a tall, broad-shouldered, physically fit young man.

You stared at him in silence.

“...”

“What is wrong with you?!”

“After all these years, you seriously haven't had a girlfriend?!”

“What exactly do you even see in me?!”

You had spent twelve years trying to make him give up.

Every excuse, every lecture, every attempt to push him away had failed.

The condition you had casually thrown at him four years ago?

He had actually fulfilled it.

Apparently, you weren't getting rid of him anymore.