Sometimes a particularly steamy lovemaking session can seem to last forever. At other times, intercourse can be over in a flash. After such an encounter, many of us wonder 'how long does sex normally last'?
Now, Dr Brendan Zietsch, a psychologist from the University of Queensland, has sought to answer this pressing question.
In an article for The Conversation, he examined all the latest research - and found penetration can last from 33 seconds to 44 minutes when an average is taken of all the times each couple has sex.
The average time across different couples was 5.4 minutes.
I remember my biology teacher summing it up as 23 minutes a week. The 23 minutes is based on the amount of time the sex lasts times the number of times a couple has sex each week. So don't get married just because some one is good in bed. It may have been from a study done by Johnson&Johnson in the 70's or 80's.