When a couple comes into my therapy office, often one person will say, "I just don't understand my husband/wife. What s/he's doing makes no sense to me. S/he's behaving completely irrationally." At first glance, this may seem true. But, I have found that people actually do have some kind of "logic" underlying their behavior. There is a reason for why people do what they do -- or don't do. But, the "logic" behind someone's behavior does not always make sense to that person's life partner.

There are a few reasons why someone's behavior is not understood. Often the person may be reluctant to share their "logic" with their mate. Sometimes it may contain information that may be upsetting to their mate -- such as, "I do this during sex because I'm not really all that sexually attracted to you anymore and it helps me get aroused" or "I'm not having sex with you because I'm having an affair."

There are also some instances in which the "logic" behind the behavior is not even known to the person who is behaving in accordance with it. That is when an experienced therapist can help the person uncover their "logic" and then share it with their mate.

What's an example of this? If a woman feels that she lacks control in her relationship in ways that really matter to her, she might unconsciously be looking for other ways to regain that control. She might withhold sex. Or she might start to have sex and then "lose interest" midway through and have "no idea why." Others looking at the relationship could argue that indeed she has a great deal of control in the relationship since sex is a fairly powerful aspect of most relationships. But until she thinks differently, the opinions of others will not matter and she might continue the sexual starvation diet for her partner while not making the connection between that and the other aspects of her relationship.

So, for such a woman, sex may be the area in which she equalizes whatever she may feel is out of balance. She may not be balancing the spreadsheet consciously, but it's going on anyway. Once she and her partner understand this, they can consciously look for ways to keep the relationship "in balance," rather than be at the mercy of this kind of emotional math. Ideally, a sex therapist could help discover these issues and minimize the blame -- from there they can see what is possible for their relationship.
(source: blogs.webmd.com)