Even the most hardcore Potter fans don't know everything about the famous wizard and his quirky friends.  That's because author JK Rowling is constantly adding new background stories to the much-loved series. The seventh and final instalment of the Harry Potter book series was released in 2007 but JK is still keeping fans gripped by releasing new tidbits about our most loved and loathed characters on her website Pottermore. One such character is Harry's cousin Dudley Dursley, who turned 35 this week. To celebrate, JK has brought us back to 4 Privet Drive and finally revealed to fans why Harry's Uncle Vernon and Aunt Petunia Dursley were so cruel to him. Fans will already know that the Dursleys disliked magic and resented Harry's mother Lily but what we didn't know is that there was a specific incident that marked the breakdown of the family's relationship. So apparently, when Lily invited her future husband James Potter to meet Petunia's fiancée Vernon Dursley, things did not go well between the pair. 'Muggle' Petunia had feared Vernon's reaction to the magical couple Lily and James and it turned out her worries were justified. J.K. wrote: "Vernon tried to patronize James, asking what car he drove. James described his racing broom. "Vernon supposed out loud that wizards had to live on unemployment benefit. James explained about Gringotts, and the fortune his parents had saved there, in solid gold." When Vernon couldn't figure out if he was being made fun of or not, he got increasingly angry and eventually he and Petunia stormed out of the restaurant leaving Lily in tears. Following the blow up, the Dursley's did not attend the Potters' wedding or indeed Harry's birth and only very grudgingly took him in when he was orphaned . The rest is history.