Our only recourse. But you're not completely safe at home either.
Yesterday, our five-year-old next door neighbor told my 6-year-old daughter that he wanted her "to get naked."
And the way the girls dressed at my 15 yo son's confirmation class banquet this weekend...it was all I could to not to ask if their next stop was our local "red light" district. Of course, my 15 yo did not know what that was. ;-)
I wish more parents cared about protecting their kids' innocence.
Of course you know the five year old and the circumstances, but I can tell you as an experienced father and grandfather that many children starting around the age 5 think the word "naked" is hysterically funny. There isn't necessarily a sexual component in it. That said, I'd watch that 5 year old like a hawk around my daughter.