From The Guardian:
It was on a long train journey that I first read Junichiro Tanizaki’s novella Diary of a Mad Old Man (1961). It had been sent to me by an American friend who knew I’d just read Tanizaki’s novel The Key (1956). The Key concerns a middle-aged, ordinary couple with an adult daughter who still lives with them. From the ruins of what appears to be a long-dead marriage, something starts to stir. We like to believe – it is a common misconception – that erotic relationships only deteriorate, that there is nothing new that can happen between a long-established couple. This is something we are so certain of that it must be incorrect. A deep involvement may become so distressingly pleasurable that we might feel dangerously addicted. As such a relationship develops, distance might be required, as the relationship begins to feel dangerous, even incestuous.
The novel opens with a middle-aged man drugging his sexually cold wife in order to spend more time with her feet. The sexuality of both of them is in the process of being re-aroused by the constant presence in their house of their daughter’s fiancé. Here jealousy makes passion possible. As Lacan puts it, “The other holds the key to the object desired.”