After breeding a few times, body parts will increase its base size and max size
Viewing post in future changes
You should do that with the penis too. Also is there any way to keep the third size? (the one with the veiny penis, open nipples ecc.) and if not could you implement a way to get that?
To clarify i know that the more birth xp you get with a body part the bigger it gets but i have 30 penis birth xp and i'm still at the second level of size.