Silly, random idea for a new pregnancy system:
The sperm has to fight the egg to get in.
The stronger the mother, the stronger the egg.
Ryen's sperm gets experience and gets stronger by getting more girls pregnant.
The systen would be optional, with an option to enable/disable it.
It could be for replay scenes, so that you don't get bothered during the first time you play a scene, and so that you get an alternative way to get certain pregnancy even without the pregnancy potions.
The battles would use the existing battle system, but with groups of sperms as your "party members" and unique skills to make the battles a bit different from how the normal battles work.
What do you think about the idea?