The Kiss by Danielle Steele

First kisses are often explosive, but not all are quite as disaster-ridden as the one that propels Steel's latest romance. Isabelle Forrester, elegant and refined wife of cold and indifferent Paris-based banker Gordon Forrester, has spent most of her marriage caring for her desperately ill teenage son, Teddy. Isolated in her Paris home, Isabelle's only comfort is her long-distance friendship with millionaire Washington power broker Bill Robinson, also stuck in an empty marriage.