the sub-consciosly *Only,
scent a female puts off
(Not Perfume! - natural female smell) will attract males and automatically cause biological responses such as a hardone.
works other way too,

females getting scent(again natural, NOT manufactured for profit ) of a male which is a *good biological 'mate' for making babies gene-wise will often adjust ovulation to be conducive to mating that individual male,
-provided the female is not on any hormonally based birth cuntrol such as the pill, etc. this is thought to likely be why while Not personality-wise attracted to an opposite gender person, they still seem to be in your thoughts frequently, it's a mother-nature connection for good biological matches proCreatively speaking.