A vein twitched in Harry’s forehead, annoyance spiking. He had not known that. Regulus had never really mentioned it; Harry had intuited it. He’d been blatant in his dislike for Dumbledore, but he hadn’t really spoken of the criticism towards Slytherins. Like it was just a known thing. Like it just was. Something accepted by society. Something simple to wrap the mind around. 