Thanks. I think I've done the best thing I can, accept the request but put settings so he's very limited in what he can see, will also 'unfollow' (but not unfriend as that is something he would know about) so I don't see his posts.

Hoping, that is a really good point about having him as a future contact, I didn't even think about that. Sometimes I don't see what's at the end of my nose.

I think I'm basically cross with myself because I told myself I would never add people unless they were friends and now I find a good smattering of those on my friend list are not. It's kind of a cognitive dissonance.