Yoongi went out to eat dinner with his kids Jimin, Jungkook, and Yugyeom. While at the restaurant, Kookie and Yugyeom are playing around and ake a waiter drop a tray of food. The waiter gets mad and grabs them and starts yelling at them. They start crying aND Yoongi confronts the waiter. The waiter pushes Yoongi around because he is smaller than him. 

Don't really have what happens but either 

1) Taehyung steps in because he doesn't like what is happening 

2) Taehyung doesn't find out till one of the kids tells him when they all get home (he sees a bruise from where the waiter grabbed the child)