I love him a lot but he really is an anorak - and he's bringing our ds up to be one too.
He's just explained to me, in great detail, the track layout he and ds built this afternoon with ds's wooden trainset. Apparently it's a Virgin Southern Somethingorother, with all the termini and various major cities along the way. He's a little bothered by the fact that the northern section (Birmingham to Glasgow? God only knows.) isn't to scale.
I think I'm going to have to read him a thread about Mooncups.