"Birds do it, bees do it and even educated fleas do it." And no, unlike the song, we’re not talking about falling in love here; we’re talking about the beast with two backs. It’s a subject that we never tire of discussing, analysing, gossiping about or alluding to, but if anything’s going to cure you of insatiable curiosity and speculation it’ll be 'The Inner Circle'. In fact, it’ll have you turning off the Marvin Gaye and reaching for your chastity belt faster than you can say: “Honey, I have a headache”.

It’s really no surprise that you tire of hearing about sex when the subject of the book is Professor Alfred Kinsey, the pioneering sex professor of the 1940s, whose biographical movie was nominated for several Academy Awards this year.

The main character in this fictional reconstruction is John Milk, a sexually inexperienced senior student from Indiana University, who is coerced by another student to attend Kinsey’s lectures on sex. The lectures are groundbreaking because they cover everything about sex, a subject which until then (1939) had never been discussed openly.

Quite hard to believe given the sexually-liberated atmosphere of today, but in those days sex was incredibly taboo and never spoken of in public; even rarely mentioned in private.

Milk is so impressed that he agrees to an interview with Prok (Professor Kinsey) where he gives all the details of his (meagre) sexual history. Prok is, in turn, so impressed with Milk that he hires him as an assistant. Such is the professor's charisma that Milk is drawn to him as a father figure, role model and sexual partner — even though he’s straight and Prok is happily married.

Kinsey, however, believes that sex is not emotional but rather the function of human animals, meaning that all forms of sexual deviancy are natural. In fact, the only things he views as abnormal are abstinence, celibacy and delayed marriage.

Prok is already fanatical about his research but Milk soon shares his passion, joining the researcher's "inner circle" — where there are no secrets, although the goings-on must be kept secret from the outside world.

Although "The Inner Circle" is a well written and interesting read, after a while the subject of sex gets, frankly, a little boring and tedious. You just wish that Boyle would describe the characters shopping rather than getting aroused for what feels like the millionth time.