"But you look so cute in your little red pinafore..."
"No I don't! I don't look cute in anything! Admit it, nothing suits me! Whatever I wear, I'm still this plain ugly girl nobody takes any notice of! I could wear a trash bag and it wouldn't make any difference!"
"Pet, you know that's not true!"
"Yes it is! I might as well just stay here! You go off to the wedding without me, with your perfect little Lily who looks cute in everything! Nobody will care if I'm not there! They'll be too busy gushing over Lily and her perfect looks and her perfect behaviour and her perfect abilities and her perfect grades and her perfect everything!"
"Petunia! It's your cousin's wedding!"
"I don't care about my stupid cousin's wedding! Just leave me here! Go and enjoy yourselves!"
"Petunia, please...it's not like you to be jealous of little Lily!"
"Oh yeah? That's what you think, because you've been ignoring me ever since Lily got that letter from that freak school she goes to!"
"Petunia, how dare you! I have certainly not been ignoring you!"
"Yes you have! You're prouder of Lily than you are of me!"
"That is not true, Petunia Evans! Apologise at once!"
"I won't apologise! You deserve it!"
"Petunia! Come back here!"
(no answer, except the sound of muffled sobbing).