I bumped into a parent and doctor on the flight recently who said "Let kids get a lot of touch at home from their parents. Daily. Especially from the parent of the opposite sex. Even mock wrestling, cuddling, whatever. Only then will you empower them and they can instinctively tell when it is good or bad touch." This I think is wonderful advice.
On the other hand, though maybe not that often, one hears of parents/ siblings/ grandparents being abusive. If that is the case, God forbid, your child is likely to sense it.
Do listen to what he/ she has to say. He has no one else to turn to.
Do not dismiss it though you may want to. Do not judge them. There is no room for embarrassment/ denial.
You are not the victim. They are. Please save their smile.
It is Child Sexual Abuse awareness month this April in the blogworld. Initiated by two well known and committed bloggers, Monika and Kiran, this has spread to include a lot many contributors.