Deep Desire to Impregnate Women
It's as simple as that. I've had a fetish to breed with any willing and capable female, then do it again if she wants or move on our separate ways. It's not just the sex and pumping a load into a fertile womb, but knowing that I'm the cause of the changes their body is going through, is beyond satisfying for me. I've had it accomplished once by a online acquaintance (who was cool with being a single mother again), and ever since then it's progress even past a fetish.
I never imagined there'd be a woman like that, and ever since then I can't stop wondering if there's more women out there looking to simply procreate.