The first rule when it comes to you and sex, according to sexologist and author Yvonne Fulbright in her book Sex With Your Ex… And 69 Other Things You Should Never Do Again (Adams Media), is to do exactly what the title says. Don't allow yourself to get back in the sack with a past love. As Yvonne says: "You're playing with fire on too many levels. There is a reason - probably several! - that this person is your ex. Physical intimacy will bring back feelings you think you've buried, which might confuse you and cause you to make decisions you might later regret."

Do you agree? Is sex with an ex no-go? Tell us below.