No, voyeurism is not a focus for the story. However, this is a story-based game, not a dating simulator. So, the times that other people are shown having sex, it is either for character building, or giving the audience a sense of a locations environmental setting, ambiance, or culture.
The MC will be the only male character used for any sex focused scenes.
There will be no MMF, swinging, or ntr. Some of the girls will be in varying types of relationships, but aside from some girl on girl scenes, there won't be any scenes showing sexual relations with other guys, outside of potential pda and that'll only be if it's needed to tell the story, set a scene, or for character building.