Kim Kardashian chatted with Jay Leno last night about her engagement and upcoming wedding to Kris Humphries, and Kim gave us more details than ever about the proposal, the prenup situation, and any changes she'll make to her name. Of the proposal, Kim said Kris had rearranged the furniture in her room (pretty gutsy considering Kim is someone who can't even film a Just Dance 2 for Wii without worrying what kind of dirt the central air is blowing off the boom mic) and on a big white rug, he wrote "Will you marry me?" in red rose petals. The audience thought that was adorable, and then she made the charming switch to talking about the reason why she decided to draft a prenup. She explained that her father (the late Rob Kardashian) had her sign contracts for everything, like for cars and groceries and so signing one to get married just made sense to her, and she said she didn't believe it lessened the love she and Kris have for each other. Kim also explained that she will legally change her name to Kimberly Kardashian Humphries, but she'll remain Kim Kardashian for all business related things because she curiously didn't seem to believe she could change the Kardashian Sears Collection to the Kardashian and Humphries Sears Collection. And finally, she told Jay about how Kris went about the process of buying a ring -- and as suspected, it was by getting help from one of Kim's jewelry designing-friends who knew exactly what Kim wanted in a ring. Natch.