Lisa and I had a lengthy and passionate disagreement in the car this weekend. I sneezed, she blessed me, then I sneezed again, and she did NOT bless me! Just silence! "Hello! I've sneezed again! You are required to re-bless me!" I said.
"No," she said, "once I've blessed you, that counts for ALL the sneezes in that sneeze-group."
I say that you are required to bless someone after the LAST sneeze. I will also accept the German "gesundheit" but I think that's kind of phoning it in, and not a real blessing.
If five sneezes in a row occur, you must say "Goodness."
Anyway, I wanted to let you know that I have sneezed without a proper blessing, so from this point on, I cannot guarantee what kind of bad things will happen to me.