Break up.

Fights constantly kept happening.

Suga: I am tired RN. Can you just not.

Belle: Maybe one day you will understand why. Everything you touch it surely dies.

Suga: That was unnecessary.

But after his this behaviour Belle can't take it anymore and asked for breakup.

Suga: What is it Belle? What other fight are you going to bring up now?

Belle: I want to break up.

Suga: Why would you say that?

Belle: Loving you is a losing game.

Suga: If that's what you want. Whatever.

A week later. Minutes before concert. Namjoon notices Suga is out of it. On stage he broke down into tears.