Oh, I adore your Severus. He is perfectly in character and so beautifully portrayed... in a cutting, anal, belligerent way, of course.
The story itself was written just as well. Your attention to detail - the shop, their thoughts and idioms, and the little movements they made - captured the reader and ensured their enjoyment. Your humour and turn of phrase towards the ridiculous just added to it, making this prime story-telling. Thank you!