I think you are doing the right thing by speaking to the director and I would assume that if it was this boy, then he is probably being molested, which may explain his behaviour. So you could potentially be helping him as well.

Also, I would like to add that a lot of parents forget to teach children that their mouths are a no go area as well as the genitals. This is really important as a lot of sex offenders, can cohoax children into using their mouths. Just wanted to add that for anyone who had not thought about it. I have worked with sex offenders within my job.