Madam Kirke scoffs. "Of course it was! Sweet Circe, they don’t teach children anything these days! And what with one of you Muggleborn and the other one growing up in a family that took Voldemort’s blood purity nonsense seriously, there was no one to tell you about magical bonding. It’s a shame! Augusta, listen to this." She proceeds to explain the whole thing to Neville’s grandmother and, of course, to everyone else at the table.