The Sea by John Banville
Max Morden has reached a crossroads in his life, and is trying hard to deal with several disturbing things. A recent loss is still taking its toll on him, and a trauma in his past is similarly proving hard to deal with. He decides that he will return to a town on the coast at which he spent a memorable holiday when a boy. His memory of that time devolves on the charismatic Grace family, particularly the seductive twins Myles and Chloe. In a very short time, Max found himself drawn into a strange relationship with them, and pursuant events left their mark on him for the rest of his life. But will he be able to exorcise those memories of the past?