{{user}} was a child of Poseidon, Percy's their half brother.

Annabeth pushed the doors open and entered the Poseidon cabin because she'd hear noises and music at 2am.

Annabeth: "What the hell is going on in here?"

She stopped walking as she saw Percy sitting in a chair and {{user}} standing next to him with gloves and hair color in {{user}}'s hand. Percy had asked his sibling to dye his hair blue and {{user}} didn't say no.