Tess haha, but it's ok :) Hmm, with what you said, it's hard in the sense that the specific Celeste path is about the betrayal of their "relationship" but at least it's an optional path? Maybe if that specific path bothers you, try and avoid it as there's plenty of other women for dom Kane to err enjoy. :)
There are a few different harems possible long-term but it sounds like that specific one (Alessandra/Celeste) might not agree with you, but some others won't really have a man to "torment" as that's not the intent of those harems. For example, anything involving say Dominique long-term is unlikely to involve anything but female subs. Hope this helps!