Some people have reported that persimmons smell like sperm or semen. It may just be a coincidence that the person tasted persimmons also tasted sperm from a man who ate something that made his sperm taste or smell like persimmons.
But again, there are people who think that persimmons have a musky womanly smell.
The way you perceive smell varies from others. Your heightened olfactory senses can be one of the reasons why persimmons smell like semen.
There is no scientific evidence to prove this. Some people say that persimmons smell nothing like semen. Thus, it is not a universal phenomenon.
However, there indeed certain plants in this world whose flowers or fruits do have that cummy smell. For instance, the ornamental pear (Pyrus calleryana), which happens to be a flowering deciduous tree smells like semen because of dimethylamine and triethylamine present in them.
Both dimethylamine and triethylamine smell like ammonia and semen has ammonia in it. Basically, those trees smell like that to attract insects for pollination.
So, if you think persimmons smell like sperm or semen, get over it and enjoy the smell like memories of those steamy encounters with your man.