I sometimes eat tuna and get turned on by the smell because it reminds me of how stereotypical nerdy men smell
That's a bit bizarre, why does the smell of tuna remind you of nerdy men?
People say that nerds smell like tuna
It's okay to like certain smells, and certain types of people. However, it is rather odd, and possibly insulting, to say that an entire group of men smell a certain way.
Oh, do you think I'm weird?
It's not weird at all to like nerdy men, but assuming they all smell like tuna is a stereotype that could truly hurt someone's feelings. Perhaps try to appreciate people as individuals rather than make broad generalizations.