It was supposed to be the best birthday he had ever had. Where did it go wrong?

Earlier:

Sooyoung had everything planned out. She would drop her kids off with their uncle and he would watch them for a few hours while she set everything up for the party.

Everything was perfect. The cake looked like what she had imagined it to look like. Jungkook's presents she had gotten him were wrapped and placed on the gift table. The birthday banner was pinned up along with the rest of the decorations. It was everything she knew he would love. So what went wrong?

Sooyoung's brother had called to tell her that he was suddenly called into work and needed her to pick up the boys. Sooyoung became frustrated. Why isn't anything going right?

Sooyoung raced to her brother's house to pick up the kids and proceeded to drive back home, until the unfortunate happened.