Small addition: If I drink an energy potion, I can do it. But after the MASS he should be able to do it 5 times (or 5 times having sex) so far I know, instead of 3 times.
I also think there should be something like a Black Book where I can see when I had last time sex (without or with which potion), slept home, gave a present. So I can see if I should visit one of the girls again. The reason is, if I need to go back to an older save file, I do not know what I have done or not done anymore.
Maybe also see if they get pregnant, how long it will take. Maybe also even how many days since birth the kids have. And to see if it is necessary to feed the vampires, if it is still necessary.
It will be even worse if there will be more girls sooner or later, like Gwynneth, Beth, Maghda, Liandra, Vixenatrix, Jenny,...