Room on the Sea by André Aciman

In the scorching New York heat, a hundred people wait to be selected as jurors. Paul is reading a newspaper. Catherine is reading a novel. So begins a whirlwind flirtation: over cappuccinos in Manhattan and gallery trips to Chelsea, Paul and Catherine escape into the illusion of an Italian getaway. Their feelings quickly evolve into something deeper, something - as mature adults with lives of their own - Paul and Catherine must carry on in secret, with the understanding that anything more than a casual crush is out of the question. But as the sultry summer week draws to a close, the end of their rendezvous comes into focus, and Paul and Catherine are forced to decide whether to act on their feelings or leave the fantasy of what could have been to the annals of the past.