This species of humanoids has a peculiar way of reproducing. 

Instead of the usual physical intercourse between a male and a female, followed by the sperm cell merging with the egg cell to generate the embryo, they reproduce following something similar to what sponges, corals or some anemophile trees like pines do.

> 
> The males periodically diffuse in the air a cloud of "pollen", which
>  then is carried by the wind until it lands on a surface. If the
>  surface is the suitable appendix of a female, fecundation takes place.
> 
> 
> 

I have the following constrains:

* the female, though not controlling the fertility period, can control whether to expose or not expose the appendix.
* though technically possible, 1 on 1 fecundation is extremely disdained in their cultures. "You know who your father is" is one of the worst insults one can pronounce in all their languages.
* It's common that males gather together to spread their pollen around. Willing females sometimes gather together, too, in a suitable place according to the wind.
* Their embryo development follows the same general lines of *homo sapiens*

[![Pine spreading pollen](https://i.stack.imgur.com/2Pfme.png)](https://i.stack.imgur.com/2Pfme.png)

The problem I have is that I am not finding a way to reconcile this way of reproduction with physical pleasure for both sexes. In *homo sapiens* the nerves form before the sexual differentiation, so the basic sensitivity is already present in the areas which will become either a penis or a clitoris. But for these humanoids the female seems to have no use for sensitivity in the sexual organs. Simultaneity of the pleasure is not in scope.

What mechanism can I use to have both sexes experience physical pleasure which can be coherent with the embryo's development?