Here are the fics I've tagged asshole!john over at my Delicious (https://delicious.com/reggie11/attribute%3A%20asshole!john). Hopefully there are a few there that you haven't read. I also have possessive!dean, jealous!dean and underage tags (although there are no extreme underage fics listed) - hell, I have a huge bunch of tags that you can wade through to see if there are things that interest you.