What if it's on your mother's side or father's side? You dont have to be related directly if it's your cousin's cousin.
wait... where it say that omg?
The scooter part lol
If the brothers only share one parent then it's possible for him to only be the cousin of one of them. But it's still weird to not treat them like relatives to me. And it's a really weird detail to put in the story when the character isn't even important.
"my cousin's brother" so uh.... thats still your cousin?