Because dating MILFS and seducing young girls are so easy, that is why the net is full advice site and PUAs and self help...No. It is just a banner to show the game, nothing more, nothing less. To get that such a thing implies a harem is ridiculous.
And you don't have to agree with me. But just because you want a harem, does not mean it is a good idea. The whole game is about how the MC starts dating the mother while also seducing the daughter. If everyone is ok with that, what conflict is there? No conflict, no story. You can put other things, but they would clearly be ad hoc.
There is no way to have some problems on this way, we need extra conflicts.