Disclaimer: I'm not muscling in on JK's turf - just gambolling on it, like a spring lamb, having fun working out the literary and psychological puzzles which she is having fun setting us.
THE UGLY LITTLE BOY
The moment she met the ugly little boy she knew they'd be friends for life, even though her sister laughed at him.
When he didn't know how adults should behave towards children, and thought not hitting them with a belt the way his dad did constituted "being nice", she understood. When his anger and distress made him insult her, she made him a cup of tea and forgave him.
Her girlfriends laughed at the fat, nerdy boy who wanted to work with drills, and told her to leave him: but Petunia, in the end, was more loyal than her sister.
It's pretty clear, from the way his sister Marge goes on about him needing to beat Harry and how afraid he is of offending her, that Vernon Dursley is the product of a violent, abusive home life. The likelihood that he has no good parental rôle-models explains both his heavy-handed over-indulgence of his own son, and why he thinks that Harry should be grateful for and to foster parents who usually only abuse him emotionally.
[Note added in 2015: this drabble has been mildly canon-shafted by the statement on Pottermore that Petunia was Vernon's secretary before she married him. Dudley was conceived in 1979, when Petunia would have been around 21, so that means Vernon was high-ranking enough to have a secretary when Petunia was only 21. Still, if he was very good at his job and got promoted early he could still be only a couple of years older than Tuney.]
The Ugly Little Boy is the title of a strange, sad, touching SF novella by Isaac Asimov, quite different from his more usual spies-in-space stuff.
My Fanfiction. net how-to page, which gives advice on how to edit files in ffn, what characters will and won't display correctly etc., has been updated to take account of the May 2009 upgrade. The major essay on Snape's character, But Snape is just nasty, right?, has also been substantially updated to take account of recent discussion on the Yahoo group Loose Canon. You can find both on my website at www. whitehound. co. uk/Fanfic/ .