Someone said that a successful marriage is one that is constantly been insulated and protected from negative external influences.
There are people who are close to you and may negatively influence your marriage if you allow them. Protect your marriage from such people, if not they may sow seeds of fear, doubt and confusion in your mind, which eventually would bring disunity, strife, distrust in your relationship with your spouse.
The truth is, you can never tell for sure who may be secretly envious of your marriage, so it is very important that you keep issues between you and your spouse to yourself. But if you must talk about some issues (must not necessarily be negative), talk with only people who have successful marriages; people who can give you good counsel based on their own experiences in building a successful marriage. Never discuss your life with people who have more problems than you, because all they will tell you is how to be messed up like them! Be wise!
But my own advise is that, if you are going through any challenges, take it to GOD in prayer, then go to your spiritual mentor for counselling. Protect the integrity of your marriage and watch it succeed!