Sex for Gods

I always wondered why human sexuality is so strange and impossible to decode with logic. After my journey through the three worlds I found an easy explanation.

Sex is the fulfilling of the wishes of the four earth-spirits. We can't understand their whishes, but we can fulfil these whishes by doing sex.

Now ask yourself:
What kind of sex would the fire spirit like? Anal.
What kind of sex would the water spirit like? Oral.
What kind of sex would the earth spirit like? Vaginal.
What kind of sex would the air spirit like? Handjob.