Sophie <3 Grégoire scrawled on a notebook: that is the way it would have gone down in an ordinary relationship. But because we are talking about high rollers in the French arts scene, Grégoire Boullier dedicated a genre-bending book to the conceptual artist Sophie Calle in 2004. In return, she dedicated, after a fashion, a major traveling art show to him. Or, rather, to telling him to fuck off.