Did आप ever feel that Lily's name should have been mentioned at least once before Snape so as to see his reaction या his sudden expression change या something?Or maybe to see how he really shows his feelings about Lily that too in front of Harry?

i think that while it would have been interesting to see snapes reaction it would have givrn away the plot twist at the end. part of what made the last book so दिल rending was finding out that he had been a good guy all along and that he had this unrequieted undying loge 4 lily. it gives it और effect that u dont see his soft side till the end. i thot it was great...
was that a good answer?:)

I'd प्यार to see the look on his face if someone mentioned her.

Ya, it never occured to me but now that I think about it yes.