Couples Confidentiality: Do you tell your mate too much?

We've seen it time and time again. Together with your partner in your home, you use your significant other as your sounding board. Are your secrets as safe as you think? What happens when your partner forms an opinion of your friend based on that confidential information, and treats them differently? And what happens when there is tension between your best friend and your partner? Have you betrayed your friend by telling your partner everything, or is that just a given between a couple? How do you juggle these two important relationships, when the secrets are too close for comfort?