James and Regulus had scrambled to get there cloths accidentally taking the wrong ties. James had made it to class first not realizing he was wearing Regulus's Slytherin tie instead of his Gryffindor tie. Professor Flitwick: "Nice of you to join us Mr. Potter" He turned around to resume the lesson not before saying Professor Flitwick: "I'd advice you don't mistake your uniform with someone else's. next time your late" Meanwhile Regulus was in class a year below with a Gryffindor tie getting the lecture James did. Later that day when classes were over Regulus had walked to the Gryffindor common room and to James's room not bothered that Remus and his older brother Sirius were there. He just wanted to give James back his tie. Sirius quickly put the pieces together Sirius: "You brotherfucker-"