The backstory I thought was interesting, but absolutely nothing happened in the present tense story.

I can't completely disagree or agree with the previous reviewer when he says "nothing happened" in the present tense of the story in this book. I think that "nothing" is precisely the point of the book, the somthing that could have happened, open and honest communication and eventual growth and happiness is what did not occur. Given that, it would not have been the same story and it is a story of what has happened in the past and continues to happen in the present for many unfortunate, confused people--loss of true living and understanding sacrificed to fear.
McEwan truely is a genius in his desription of the voices in each of his character's heads, the presumptions we all make about our situation, about others, and he lets those voices carry the story to its logical conclusion given those presumptions. In the aftermath, we find out the cost each pays for being unable to expose the tender belly of their apprehensions to the other. Read it and wonder about your own similar lost opportunities.

Some novelists darken with age, expressing ever deepening gloom about the human condition as they glimpse the bigger picture. (Exhibit A: Philip Roth.) Others, unaccountably, soften. In the latter category is Ian McEwan, the British writer who began his career in the 1970s and '80s with a string of macabre books about incest, depravity, and murder, but whose more recent work glows with a sweetly romantic faith in the human potential for happiness. In particular, domestic happiness. It is not easily attained, however, this happiness of McEwan's. And it is almost always under assault — by the demented stalker of Enduring Love, by Saturday's disenfranchised intruder. In his latest novel, the exquisite On Chesil Beach, the threats to the good life are more prosaic but no less deadly: immaturity, impatience, the impulsive wrong decision.
''They were young, educated, and both virgins on this, their wedding night, and they lived in a time when a conversation about sexual difficulties was plainly impossible,'' begins this compressed, crisp, but warmly specific fable. The year is 1962, and Edward Mayhew and Florence Ponting are dining in their hotel suite on England's Chesil Beach. They are deeply in love, a state that McEwan treats tenderly and with utmost respect: ''They had so many plans, giddy plans, heaped up before them in the misty future, as richly tangled as the summer flora of the Dorset coast, and as beautiful.''
Moving gracefully between the two, McEwan captures both their shared joy and their terrible private worries, almost exclusively about what will transpire when they approach the ''four poster bed, rather narrow, whose bedcover was pure white and stretched startlingly smooth, as though by no human hand.'' Edward — eager, ordinary — fears ''arriving too soon.'' Florence agonizes not about arrival, but the journey itself. Sexual squeamishness has never been written about more adroitly or sympathetically. In a wedding handbook Florence finds ''certain phrases that almost make her gag: mucous membrane, and the sinister and glistening glans. Other phrases offended her intelligence, particularly those concerning entrances: Not long before he enters her...''
Put like this, you can hardly blame her. But toward that portentous bed and their future they proceed, Edward and Florence, with their anxieties as well as their ardent, fragile love. To reveal what lies in store would lessen the pleasure of reading this small masterpiece, though it's hard to imagine that anything could spoil it. “A”