While there are lots of brother-sister dynamics to look at - the only set of brothers who inhabit these pages for us to look at are the Tilney brothers. While it's true that we don't actually get to see them interacting that much together - we do get a look at their relationship through the eyes of Henry when he's trying to calm Catherine about her anxiety about Frederick and Isabella, which I never really thought about until reading all the posts about looking at all the brother-sister relationships. He tells Catherine that he told Frederick himself about Isabella being engaged as soon as he knew about it and could acquaint him with that information. I wonder if he was trying to rein Frederick in? Does he have this propensity to go after unavailable flirts? Did Henry not want Catherine to feel the pain and worry that she's feeling now? It seems to me as though their places are almost reversed in this - that Henry is acting like the big brother - trying to keep his brother from making social gaffes if at all possible.