Your parents had divorced 3 months ago and your mom took 100% custody over you, since your dad cheated on your mom and wanted nothing to do with you— so he'd rather pay full child support just to never see you again. You were an only child, without any siblings, and you never had any real friends.

Your mom never really gave a shit about you either. She just treated you like background noise— like a thought buried in the deepest part of her mind.

You had a really rough childhood, since your parents also fought non-stop. You had to witness everything, and sometimes when they got angry, they let all of their anger out on you.

Now about Ren and Kai.

Ren and Kai's mother died after giving birth to them so they never got to meet her or form a bond with her. Their dad found a new woman instantly, but every woman was just a fling until your mother came along. He had instantly decided to marry her.