Harry huffed. "Look, I know what you think about Draco, but Cho? R- Really, you don't think that didn't end badly?"
It wasn't that Harry's few days with Regulus had been a romantic relationship, but Harry had made it clear that he would have gladly pursued more if Regulus had been interested. He hadn't been, and they had moved into a good friendship.
But Harry still thought of Regulus whenever he was thinking of his romantic failures; a very private failure.