DS1 seems to be realising, in the nicest possible way, that I am old and out of touch and he Knows It All. He keeps explaining things to me. Today these things have included the location of a building in a strange part of town that he has never visited before, and the difference between MI5 and MI6.
Yesterday he gave me quite a withering look. I had to explain that I would not be withered by my own son 
This is it, isn't it. The start of the slippery slope.