Forgiveness is an important subject between people who are in relationship. And it’s an issue I often must address as a sex therapist.

It’s impossible for anyone to have a long-term relationship with another human being and not wind up doing something a — or many things — that are hurtful to the other person.

Of course, there are big hurts and small irritations. The small ones don’t usually result in the end of asexual relationship.

On the other hand, a couple’s diminished or nonexistent sexual relationship is often the sign that a significant injury has not been forgiven. I frequently see couples who are very good friends in many ways, but at a certain point their marriage became a sexless one.

It’s at that point that one of the partners — often the man, in a straight relationship, brings the problem to me.

It is the vulnerability inherent in an intimate relationship that makes sex the casualty of unresolved anger. Big betrayals and disappointments erode the trust between two people. (You may be surprised to hear that affairs are not necessarily the most common source of resentment that erodes sexual connections.)

You can still have a pretty good “couple life” together without sex.

It’s still possible to get dressed up and party and dance with your partner, particularly if you are proud of how he or she looks and acts.

It’s still possible to go to ballgames and cheer for your team, to go to museums, travel, or take in children’s activities and games and join in the fun and support with other parents.

It’s possible to enjoy grandchildren together. It’s still possible to go to extended family dinners, holiday celebrations, weddings and funerals — to have the pleasure and the social status of being in a couple.

But when you are holding onto hurt, it’s an entirely different matter to be naked, to wish to be touched, to have sexual longing, or to touch another person intimately.

I have hear couples say: “No darn way am I going to do that. I have no trust. I am too hurt. They don’t deserve to have sex with me.”

I always look for unforgiven resentments when taking a history in a sexless marriage. What’s sad is that I’ll sometimes unearth traumas that occurred a decade or more in the past, and were never aired or resolved.

This article by Desmond Tutu and Mpho Tutu, his daughter, is a wonderful resource for anyone who wants to begin to work on forgiveness.