If by realism you're talking about building a romantic or sexual relationship in a way that makes more sense, rather than the MC out of the blue feeling sexually attracted to the people he's always lived with, then here are some suggestions. I particularly like this type of game, even the king of blue balls
A Wife and I Mother, which, in my opinion, has an excellent story progression, despite the very slow game development. However, there isn't many games with M/S, it is more common with B/S.
Other suggestions are:
Ripples
No More Secrets
No More Money - abandoned but it has some progress
Monkey Business
Photo Hunt - kind of, but I like the progress
The Cabin - Summer Vacation - also kind of
A Long Journey - the mother only appeared in the last update, so we don't know what kind of relationship she'll have with the MC, but it's a great game and worth keeping an eye on. However, the developer's progress is very slow.
Timestamps: Unconditional Love and
Timestamps: Lost Love - the second part it's in a limbo, we don't know if is going to continue or be abandoned.
DeadMoon Survival - It's more realistic in the sense of something that could actually happen. Unfortunately it's been abandoned, but there's been some progress.
scene
