After being made John’s guardian, how does Bernard respond to his newfound popularity and importance? Why does his response sadden his friend Helmholtz?

Bernard takes full advantage of his position as John's guardian. He is popular, enjoys the excitement, and particularly relishes his flourishing sex life. Helmholtz is saddened because what he believed to be Bernard's ideals seem to have been no more than a lie. Bernard, in turn, turns his back on their friendship.