The worst part of the books which made me cry had to be the death of both Tonks and Lupin. It really had me sobbing as they had become my favorite relationship in the books and was so shocked when they died. It was not a nice moment at all. But then to have that followed by the truth about Snape, I found myself crying constantly whilst reading the last book. Everyone just seemed to be getting killed off! But the Tonks/Lupin was the worst crying moment, I just hope I will be able to hold myself together whilst watching the final film.