Felix.

Lee Felix is ​​an omega. He was 15 years old when he was adopted into a new family.
Minho, Jisung, and Hyunjin lived in the same family. And all three were adopted. The problem was, the couple who took them in was infertile and couldn't have children. All three were alphas.
Minho was the eldest, 19 years old. Hyunjin was the middle one, 17 years old. Jisung, the youngest (was), was 16. The family was wealthy and never denied their sons anything. But they raised them to be polite and friendly.
And so, Felix was brought into the house. Once settled, he didn't leave his room and was afraid of his brothers. Everything around him seemed alien.
But he had to get acquainted. And so, descending the stairs from the second floor, he froze, hearing the clatter of feet in the living room and someone's voices. The boy stopped in the stairwell. From there, everything was visible and audible, but no one noticed him. Minho noticed someone's shoes and asked:

• Mom, Dad, do we have guests?

• No, honey, we decided to take another child.
  The woman said, smiling softly.

• What?! Another one?! Why? I don't want one! I've had enough of these two.
  Minho was indignant.

• Another one?! Can't we return it? It'll just get in the way!
  Said a dissatisfied Hyunjin.

• What?! Why?! I don't want to! I'll have to share with him and help him! Horrible.
  Jisung whined.

• Give it back!
  All three said it in one voice. But who knew that Felix heard everything?