After David receives a letter from Hella announcing that she will return to Paris, he walks down to Montparnasse looking for a girl to sleep with. He finds Sue, a wealthy girl from Philadelphia that he has met several times before.
David is aggressive with her and gets her to take him home to her apartment. They have sex, and he says, "I knew that she was giving herself, not to me, but to that lover who would never come" (2.2.79). David imagines that what he does with Sue is more immoral than anything he ever did with Giovanni.
It quickly becomes clear to Sue that David just stopped by to use her and has no intention of seeing her again. Yet they play out an awkward goodbye. She smiles at him as he leaves and he remembers:
She wore the strangest smile I had ever seen. It was pained and vindictive and humiliated but she inexpertly smeared across this grimace a bright, girlish gaiety – as rigid as the skeleton beneath her flabby body. If fate ever allowed Sue to reach me, she would kill me with just that smile. (2.2.94)