Why not just interrupt him and say, 'Please be quiet.'?
I know, I am pretty good at being straight/blunt but there was just no respite yesterday, I should have got "Please be quiet" in, but I think I was shell shocked.
Anyway, I told him this morning to try to keep some appropriate distance between us as he was unnerving me, and, that everybody gets nervous in a new place with new people, it's understandable & normal but perhaps it'd be better if he looked and listened rather than trying to engage me in conversation 100% of the time we are together. But not speaking continually left him rocking backwards and forwards like somebody waiting for bad news outside an intensive care unit. The questions are less annoying.
We have people with aspergers turn up every so often for a few weeks/months, they are usually very intelligent and often v.funny once you "synch" into them and they have relaxed in your company, but this guy doesn't display any symptoms. He's just intensely annoying. I had some snack seeds today (vanilla, pumpkin & sunflower) and asked if he would like to try some, I got called away and returned maybe 5 mins later to find he'd eaten the whole friggin pack, WTF? It takes me about 3 days to eat a pack, they are horrible!
Just one day to go.