Well no, it is not a stupid question, but it is a bit difficult to answer since the variables are so infinite in scope.
However, if you have been sexually active and have been with more than one person, you may have noticed that each person has his or her own individual "aura" which is an invisible vapor that surrounds them....an individual smell, and one that becomes more pronounced with sexual excitement.
Everyone is different in the first place, and their smell or attaction can be quite different from another. You must consider that there are disparate diets involved, and hygiene habits and the use of products with various scents, or if one is on medication, etc, etc, etc.
PLUS, each person has their own pheromones which may or may not be noticible as a smell, but can definitely be a strong attraction between people. I have read that it is very strong in the genital areas. This I believe, since it is such a turn-on. But, I believe
it is a bit difficult to make generalizations.
From my experience, if a woman is in good health, practices good hygiene, and her PH balance is right, then there should not be a bad odor. She should have a fresh smell, slightly sweet or slightly musky depending on the woman. However, there are times of the month when there may be an unpleasant smell which is slightly fishy.
The same goes for men. If in good health and practicing good hygiene, then there should be only a clean man smell. I am not sure how to explain this "man" smell, since
it is different from that of a woman, but it should not be unpleasant.
I hope this helps.