At first he did not understand the feeling that swelled within him. All he knew is that whenever he thought of that person a burning feeling ate its way through his stomach like acid.

Even though he had been first, that person seemed to be more important to everyone else.

He could not name the sensation. With every moment the monster grew within him, threatening to take him over. It wanted him to make sure they didn’t seem anyone but him.

Everything was always about that person.

He did not recognize the monster. But he was sure that the sensation of losing everything that he had was surely linked to that person.

“Please be a good boy and always watch over your baby brother.”

This hateful sensation was consuming him. Soon he didn’t know if he would be himself anymore, or if he would only be a slave to this strange feeling.

Those eyes stared up at him, that person’s eyes. He was sure that he saw traces of glee in them. That person was surely happy that he was suffering.

But now, now he knew what it was.

“Look how our precious baby clings to his big brother.”

This was...

“Our boys get along wonderfully.”

… Jealousy.