So which ntr? Netorare or netori? Shame no harem but it's your choice and don't let anyone browbeat you into changing your mind.
The MC will have the opportunity to ask one (actually, two) LI about their past personal lives. I was planning to include flashbacks with scenes of these female characters having sex with other male characters. These scenes will help you understand the motivation and actions of some of the characters in the present-tense part of the game. That's all planned NTR content, and it can be avoided if you don't just ask LI about it.