Another
big possibility:
We currently have two paths. The second one, which I mentioned, is the sharing path. In the script, it’s called "pathc" and it activates when we choose the option "allowing Nicole to get closer to other men" over "another woman into the relationship"
Maybe this option isn’t actually sharing and could be considered cheating! The name of this path in the script is "pathc" which might stand for "path cheating"
Kissing only happens in this path
In other words: Nicole hasn’t seen MC in the cheating path, and she kisses the other man
But the cheating path is ambiguous; a single choice can’t solely cause this. It’s likely that a conversation between MC and FMC happened the night before, which we didn’t see
However,
cheating and netorare are avoidable—just don’t enter the "pathc" and the kissing and breast touching won’t occur
[Deviloper] must be a huge fan of puzzles