Based on the context and the answer, generate a question. 

Context: One day my sister came and picked me up , and I was relaxing in her car . I had my arms behind my head , thinking of nothing in particular , when suddenly she mentioned that my armpits stank . She did n't say it in a mean or hurtful way , but I was still embarrassed , because it was my body , and it was yet another thing I had to deal with , had to think about , had to mask , had to play down .

Answer:

the author was most likely caught completely by surprise as they were not previously aware of the issue



Why does the author 's sister 's comment most probably give rise to a sense of embarrassment in the author ?