Welcome to the forums.
In my experiences, communication has been hugely important. Even if emotional attachment is still the rule, I would communicate it, and see what happens. Let everyone know you still want to abide by whatever makes them happy - but harboring emotions usually doesn't work out so well.
You'll feel better, at least. And the people you care about will appreciate that you were brave enough to voice what you feel. Just because you feel something doesn't mean you will start doing things that go against the rules.
I myself find it impossible to have a sexual relationship with someone without cultivating some form of feelings. It's still a choice as to what a person does with those feelings.