probably something about NTR, maybe motkeyz didn't wish to bring with it the fires of hell confirming the obvious (that we are going to get the scut fucking everyone path)
That wouldn't really make sense to the story though, and what's the fun in that. This is a game about friendship and adventures. And as mentioned earlier NTR itself is a hot topic, but there's too many interpretation of what NTR is out there. 99% Of the time when people speak about NTR they speak about the less commonly liked "Neotare".
Neotare In short: Your loved one(s) / gets stolen away from you. It could be forced or not. The focus on Neotare is to get the player to feel a deep sense of jealousy.
Example 1: Someone breaks into the house and rapes your wife or girlfriend
Example 2: You get cheated on
Scenario 1: You want to seduce your married neighbor. You may have flirted with her, or just thought about beeing her, but she's in fact still in a relationship. She probably has a sexual relationship with her partner. If you as MC spy on them, is this really NTR? No. You may feel jealous, but it's not Neotare.
Scenario 2: Your wife starts fucking the neighbor. This is Neotare.
Netori In short: Polar oppposite of Neotare. You seduce others regardless of their relationship status or interest or involvement with anyone else.
Example 1: You seduce a married person
Example 2: You steal someones girlfriend
Scenario 1: MC seduces married neighbor. MC and the interest may or may not justify this somehow with their current life situation, either unhappiness in their current relationship or just lust or whatever. Most games out there, like this one is more on the Netori path. But remember, Netori causes Neotare to the side of things.
The point is, some people will be very quick to scream out "NTR" on games where any sex scenes goes on without the MC, especially if its a man seducing a woman you have interest in. But sex happens between people in the world, if the MC doesn't want to see it he can choose to ignore it and move on. That's where the "Optional" flag comes in. It's there for the story and character development, not to block MC.
In the game
Examples of potential NTR in the game that is questionable:
Depending on your path It could be said that Bacon experiences some light NTR. But when you think about it. If you are are seducing Heather, you are doing Netori, causing Neotare on Bacon.
Summary
You cant have Neotare in a game without Netori on some end or visa versa, depending on who's side you are looking from. If someone says that there's some real NTR going on on the MC in this game, i'd really like to ask where. There's a big difference between wishful thinking on MC part, and having him denied to cause jealousy.
/A
Edit: Formatting