Dumb as it seems now, Harry’s only just realised that while he’s friends with all of these people they aren’t at all mates to each other. Instead Harry would spend time with Hermione and Neville, or Luna and Morag, and Theo, whenever the other boy could sneak away without Slytherins like Malfoy noticing. Neville and Luna are friendly, Harry’s fairly certain, but nothing about the others seems certain at all.