Thanks everyone for your responses.
Firstly. My daughter is antibrexit!
I was really pleased that she told me about this issue. Such trust is not a small thing to be easily disregarded. I raised the idea of contacting the boys parents and she was horrified.
She knows I'm a Mumsneter and so I suggested asking you wise people, DD agreed to abide by majority vote,
I'm thinking this may be seen as manipulating mumsnet if so sorry,
Obviously if I didn't get the result I'd wanted I'd ask for another vote.
DD is ok with idea that I contact school tomorrow but as an 'anonymous' report.
FWIW I haven't looked at site, their idea of inappropriate may hopefully be ? I don't actually know, but they are very sheltered easily shocked children.
As are all children we would hope.
The boy in question is a lovely boy from a nice family. Of course I know this may mean nothing,
Thanks anyway x