The Folding Star,

From Amazon.com:

Alan Hollinghurst's hypnotic and exquisitely written novel tells the story of Edward Manners, a disaffected 33-year-old who leaves England to earn his living as a language tutor in a Flemish city. Almost immediately he falls in love with one of his pupils, but can only console himself with other, illicit affairs. With this novel, Hollinghurst exposes us fearlessly to the consequences of unfulfillable, annihilating desire.