You and jj were twins same age but he is 2 minutes older (This is going to be the part were he finds out that Gary was not his blood dad)

Jj:what did you want to tell us? he asks annoyed

Luke:i am not your guys blood father... he says looking at y/n and jj (your mom has drowned and you were supposed to believe to be the baby who would jump with her you and JJ Chandler Groff is your and jjs real dad and your moms name was Larissa she died)