Ehhh, not because of MC, not as of now at least. Many games has it so the MC has giant cock, but in this game it's more realistic. Maybe in the future though!
Maybe could add some futuristic tech that helps the MC make their cock larger?
Also I was about to request some monster girls but then you said this is supposed to be more realistic so... I guess I won't do that hahaha
Only thing I can think of is the kink "impregnation request". Unsure if it's in the game or not. Basically it's just the girl begging to get knocked up.