You should read Dear Enemy. I am amazed I have and you haven't :-)

I think it's the way that Jervis tries, but so comprehensively fails, to manipulate Judy that I like; rather than being the experienced older man who knows best, he's the butt of the narrative joke as much as Judy is. She doesn't put two and two together, but in return he has to read letters not about how amazing he is, but his ridiculous clothes and the other young men she's going to dances with.