PASSION by Peter Nichols
"Is it possible to love any human being without being torn limb from limb? No one was ever made wretched in a brothel; there need be nothing angst-forming about the sexual act. Yet. . . when sexual emotion increases to passion, then something starts growing which possesses a life of its own and which, easily though it can be destroyed by ignorance and neglect, will die in agony and go on dying after it is dead."
Cyril Connolly, The Unquiet Grave
This might be the text on which Peter Nichols elaborates...