Warning against adultery.
I have always heard that if you think you are safe in your relationship then you probably arent. The worst thing you can say is it can never happen to me. To make sure that adultery or other things never happen to you is to be open to the fact that something could happen and you take precautions against it.
I had before I got married had it in my mind that I would not go to lunch with another man that was not a relative. Even if it was business. I would either have my husband there or a female coworker. Some people think that is going overboard, I would rather go overboard and do everything that I can to keep my marriage safe instead of thinking it could never happen to me and neglect the gift that God has given me and that is a loving husband and a great marriage.