More embarrassing for an older brother or sister?

Which do you think was more embarrassing, an older brother watching a younger sister or an older sister watching a younger brother take the examination?

In my case I had a sister two years older and so there wasn't much difference, however I still felt ashamed, and that's why I always tried to turn my back on her and not let her see me being examined.

@maria_fetish I suspect the worst case would be an older brother watching a younger sister. Boys are used, to some extent, to be asked to disrobe in front of older females, the converse is rarer.

I was an only child, so I'll never know.

I was examined with my younger sister until I was 16 and she was 12. We both stripped down to our underwear at the beginning of the exam. The exam ended with our underwear off. We both witnessed each other being examined. The view at the time was that it was no big deal, it's just what happens at the doctor's office. I remember being confused by this because I felt very strong feelings of both embarrassment and arousal. I feel that we were both embarrassed to be examined in front of the other and aroused to witness the other being examined.