We can see that Impregnation/insemination are BEYOND creampie. Its the 'ultimate fate' of it.erfectplan:
I think Impregnation are the most 'normal' fetish out there.
For sex stories material, impregnation is very common, to the point a whole community website dedicated for it.
It's pretty common theme in hentai.
In hentai, cross section/xray view (where man's penis clearly shown to ejaculate into girl's womb) is common, even to the point where the sperm piercing girls' eggs...
JAV with Impregnation/Insemination Theme