Female bodies are NOT opportunities. That opportunity does not exist. I don't care what she's wearing, how she smiles at you, or how quickly your moron paycheck makes you think your penis grows. Keep your hands to yourself unless she says VERY PLAINLY that you may proceed. It's no more difficult to do that than it is to NOT steal the diamond bracelet in the display case because the jeweler turned her back and you were therefore TEMPTED.
That would certainly be the end of the Romance genre! It would also be the end of most human courtship, since most signalling is non-verbal, and much of it is begun by the woman, with glances, closeness, and touches. I don't think even the Puritans attempted to enforce 'yes means yes'--though, according to David Hackett in Albion's Seed, it was the Quakers who were really strait-laced. On the other hand, those societies had clear limits, based on formal courtship and marriage--unambiguous gates that we have abandoned.
Those rules worked, being suited to both human nature and to the society they had. What rules are proven to work in the society we've become in the last two generations? We're in the midst of a massive experiment with our society, with the routes of retreat apparently cut off. How many people will you condemn for trying to find their way in the absence of proven and universally accepted rules?
