The brother relationship is great in this but it does highlight how Sam from the beginning has led a more entitled life. Dean is going the emotions of extreme betrayal, its not even about breaking the seal--it's about the season long lies and betrayal of Sam consistently putting Ruby ahead of Dean and taking the word of Ruby. What makes Dean's reaction so true, is that Sam knows that Ruby is a master manipulating Sam as she did about being able to save Dean. Sam was warned by not only Castiel but Chuck and Pamela that what he was doing was wrong, but again, again he listened to Ruby.
Sam being upset that he's not trusted or forgiven automatically, yup, spoiled child at its best.
Sam being upset that he's not trusted or forgiven automatically, yup, spoiled child at its best.