Routine is bad

The trouble is that many couples do get locked into a fairly predictable approach to their own sexuality and that of their partner. A rigid routine, in terms of time and place, followed by a predictable approach during every lovemaking episode can tire anyone's desire for sex.

Many couples could – if they were so inclined – put a stopwatch on their love-making and find that intercourse took place at the same time of the week and in the same place, and that its duration varied by no more than a few seconds each time.