By Ariane Sohrabi-Shiraz How would you feel if you found out your wife cheated on you more than 18 years ago? If you found out your partner was unfaithful you would likely see it as a serious breach of trust, and you would most likely be devastated. But would it make any difference if you knew it happened more than 18 years ago, before you were even married? When a man found out his wife had slept with a whopping 26 different men he was understandably devastated, but as it had happened when they were at university, she didn’t think it mattered. Now the man is considering getting a divorce – or…