Too much protien intake or hormone imbalance
It depends on.. If the girl really like the boy she probably love everything about him, even the smell of sweat.. but usually the girls don't like the smell of sweat. So I recommend you to use deodorant..
sweat.
A car may smell like sweat due to gym clothes, or other workout clothes, being left in the car.
Bad.
Ammonia smell in sweat can indicate a high protein diet, dehydration, or kidney issues. It is important to stay hydrated and consult a healthcare professional if you notice persistent ammonia smell in your sweat.
it smells sour (bad)
I don't know, but I like do smell another place of the girls.
Sweat, shame, and semen.
Bacteria reacting with sweat
It depends; did you wash it?!
Silicone smells like vinegar because it contains siloxanes, which are chemical compounds that release acetic acid when they break down. Acetic acid is the main component of vinegar, so the smell is similar.