This is so familiar. Mother in law had this down to a fine art. As soon as you'd say it was time to go, she'd launch into another long story, like Ronnie Corbett's stories only not so funny. Used to think it was quite endearing but, bloody hell, it's genetic. Now Mrs SL does a fine impression of her maw. Always when I'm in the middle of something or just wanting peace to read. And as if by magic, there she is, "put the kettle on". FFS.