I read Schnarch's book on when partners have differing desires for sex (he argues that there is ALWAYS lower desire partner and a higher desire partner - that this is completely normal and it can be addressed in ways that can bring people closer). I thought it would have helped my relationship with Beloved but she did not want to try anymore. So I don't know if his ideas would have helped us or not. But I found them compelling and useful and will try to apply them in my next serious relationship(s). Do be aware that he does believe that monogamy is the only real way to develop intimacy. He sees no value in ethical non-monogamy or polyamory. I have not read Passionate Marriage but I believe his ideas have not changed.