SueSeeksGent: THANKS to you all for your input, it seems tobe getting more and more complicated by the minute, with issus being raised that I hadn't even thought of.
It wasn't on a site like this, it was more of a definate dating site, not one where you can chat on forums like this one. As for letting him know that I know, well I think he may already because you can see who has viewed your profile. And as for staying out of the situation, not sure I can do that, don't think I'd be a good friend if I did and also I think that I would want to know. (hope this all maked sence).
I have been in this situation twice, not with dating sites, but friends partners seeing other women, one
time i did tell my friend, she doubted me at first then asked around and found it to be true and thanked
me for telling her.
The other time i said nothing my friend found out and also found out i knew about it, i tried to explain
why i had not told her, she said she felt i had betrayed her to and i lost a friend she has never spoken
to me since