The whole 'knock-before-you-enter-she-hates-it-when-you-don't' proved to be a casualty - apparently Kurt was hired the minute he stepped into the shop, a thing that would have been nice to know beforehand so he didn't have to talk too much to Sebastian. But Kurt has been raised to be the bigger person (sometimes much bigger), and so he braces himself for being somewhat civillized when in Sebastian's vicinity. "Thanks for the assistance"