Looking up an old flame?

Ever so innocently you look up that special someone from your past and manage to track them down. Your old flame is thrilled to hear from you, you start chatting online, meet for a drink and before you know it, things get completely out of hand. All of a sudden, you’re in bed together! 

A (married) friend told me a story of being invited for coffee in the middle of the day. Persuaded to drive to the old flame’s parents, the short journey became one of burgeoning passion, recounted later with great glee. 

If these feelings of instant trust, instant liking, instant friendship and often instant lust are so good, are we torturing ourselves if we meet someone from the past?