Thank you very much for your response, this is very reassuring. I don't think my son was more involved, as I was always nearby - but then I could not be 100% sure..., so I guess I have to leave it as that?
Although I am usually quite relaxed, the manner it which it all happened made me worry a lot, in fact I felt almost disgusted. I think it is also because this boy was offering my little one chocalates to come in his garden and I used to ask him ot to give him any (thinking only of my sons teeth), also calling the kids under the table...it all gives it a sense of planned action, which makes it much less innocent for me. Would you agree?
I will take your advice and keep my little one away from the 9 yr old (without being too forceful, at the end all the kids are playing together outside ).
A final question, please: Would you warn other mums (I don't want to stigmatise the boy, but then others may be at risk) or tell social services who are already involved with that family? My little one also goes to nursery 3 hours a day - shall I make them aware to look out for any copying behaviour (but then he never did anything at home).
I thank you a lot