Why do you people insist on bringing reality into things with this game? And I don't know if it's better or worse that it's only ever in such a limited fashion too.
People will write theses about how realistic or not our getting any of the older women will be, completely ignoring how unrealistic having a harem is not to mention all the incest and the possible effects of incest on pregnancy.
That said, and to preempt such counterarguments;
Yes I'm very aware that polyamory is a thing. But this goes well beyond that.
Yes I'm aware that inbreeding doesn't cause a massive chance of birth defects in the first generation, and that that increase is itself lessened outside of immediate family. Cat is our first cousin, so any increase with her would be limited, it's be similar with out aunts and grandmother.