Felix being your sibling includes:

   • everyone says y'all look alike but you just stare at each other with looks of confusion.
        - "I don't see it."
        - "Of course not I look better than you."

   • when you walk past each other he is quick to mumble loser under his breath.
        - You quickly mention he's the loser and run away.

   • he gets in trouble with the masters when he hits you after you started the fight.
        - "Y/n started it!"
        - "Y/n wouldn't do that, just look at him/her/them, they couldn't hurt a fly."

   • He finds your secret snack stash and eats them himself.

   • neither of you apologize after an argument, you just poke your head into each other's room and ask if they want food.

   • When either of you are enjoying peace and quiet the other will just enter and smack the others forehead and run off laughing manically.