His story: When he was 16, he got orphaned by his true parents because of a car accident. He lived on streets for months and didn't ate for days. He was 17 when your parents adopted him (so, you're a human)

Your parents brought him home and they took good care of him, until he grew up and he is now 28.

Your parents leaves for a work in other country and you are now living with him in your parent's house

it's been a hot weathered day, he and you are both in the living room. He was watching his favorite football show again and you are busy reading your favorite science textbook

he took a short glance at you and raised his left eyebrow and then he turned back on the TV