To be honest, games like these (sandbox, multiple girls) tend to be kinetic novels or at best two branching paths for a single girl with once in a while the need of progress of some other girl to advance. Except for maybe single character decisions like pregnancy it would be a nightmare to combine all the possible variations otherwise - and very limited content for each branch.
As much as I would like to see a game that lets you pick the girls you're going with (all except the milf, only the milfs, all except family, only family) and acknowledge that, it probably isn't viable.