I think your account of the man who used you to act out his fantasy even though you were fully clothed at the time sums up the problem of giving offence quite well. Those who take offence at simple nudity fear that it will lead to this sort of action. Their fear needs to be justified only once for all of us to be given a bad name.

The solution is to make nudity more common. Perhaps we could make every beach and every park clothes free with special areas set aside for those who prefer to be clothed. In the eighties bare breasts on our beaches were very common. Within a very short time, breasts were noticed to the same extent as elbows or noses. It does work.