When you come to know that your spouse has been cheating you, you may feel so agitated that you feel like sharing your feelings with someone. You may choose to confide in with your best friend, a close relative or someone who is a mutual friend of you and your spouse. However much you may like to pour out your feelings to someone and get some relief from your feelings of discomfort, embarrassment and anger, you should ponder over the idea before you rush into confiding in someone.
You need to consider two questions, whether you should confide in somebody at all and if you should, whom you could confide in.
Think about what can be wrong in sharing your agony with someone. What could be the fallout of your doing so, what problems you could face in future, how your spouse could react if they learn about this in future are some of the questions you need to find answers to decide whether you should talk to someone about your cheating spouse.
If you decide to talk to someone about your spouse's infidelity, then you have to decide whom you could talk to. You can't choose a person based on their closeness to you or on their being your well wisher. You have to consider the following:
1) Since the person you are confiding in is likely to give you some advice, can you evaluate that advice and take your decision or will you be influenced by what that person says and act on that? The advice of the other person will be based on their own perspective and personality and may not be in your best interest. In such a case, you may have to regret your action later. So choose a person with whose judgment you are likely to agree with.
2) You should be able to tell the person what you want and that person should be able to relate to you appropriately. If you tell your friend that while you are upset by your spouse's infidelity, you don't want to break with your cheating spouse, your friend should be able to give you advice appropriate with your objective.
3) The person you are confiding in about your cheating spouse should have an open mind. They should be willing to accept your decision even if it goes against their own advice. Some people are so egotistic that they will be upset that their advice has been ignored without appreciating the fact that you are doing something in your interest.