When is a hug "sexual harassment"?

I had a poignant example of this when working as a Social Worker.
A young man of 18 years with Down's syndrome moved from the chidrens' home (where he had been treated as a lovable/loving infant and exchanged rewards of hugs with his carers) to an adult sheltered environment.

On his first venture into independent life he had approached a young woman on the street and unexpectedly greeted her with a warm hug; she was understandably taken aback and felt that the incident ammounted to an "assault".

Finding the "right age" at which "normal" development involves touching and "sexual exploration" and where "inappropiate sexual behaviour" might even be an indication of sexual abuse is not easy as developmental rates can vary from child to child.

My own personal feelings are that, for many, 11 years of age is a little young to discuss details of fellatio or sex toys unless the youngster requests information themselves having heard something in the playground or on the net. I'm not really suprised that a child of this age could be made to feel acutely uncomfortable by his mother discussing her personal sexual activities with him.