I assume, although I haven't completed any research, that most people, at least those who have not experienced infidelity in a relationship of investment, believe that infidelity is mostly about sex.

Infidelity does have sex at it's core, or at least the phenomenon of developing a strong attraction to another.

So, sex or "chemistry" or sexual/emotional attraction does play a central part in infidelity.

However, this attraction takes on different flavors and different mind-sets for different kinds of infidelity.

In my Ebook on infidelity, Break Free From the Affair, I outline 7 types of affairs or marital infidelity.

The second type of these affairs I expound on is: "I Can't Say No!"

This type of infidelity has at it's center the pull of sexual addiction. The role and place of sex in infidelity cast different shadows the other kinds of infidelity.

Let's take a closer look at Infidelity and Sexual Addiction in the "I Can't Say No" affair.

The first question: People truly can't say no?

I beleive we all have the capacity to choose and say no, if need be.

However, some appear to lose that capacity, or strongly believe they lose that capacity over a period of time.

The first step in Alcoholics Anonoymous points at one's powerlessness over the object of addiction.

For some, it appears they come to a point of being entirely incapable of saying no to a strong object of desire.

Let's take a look at some characteristics of this kind of infidelity.

Acting on one's sexual impulse becomes a frequent activity. Sexual release becomes the ultimate goal. There is also an element of sexual conquest or the need to seduce and "score." A game is played out (online, in a bar, etc.) and the other person is pursued until s/he is "had." This may or may not include sexual intercourse.

(I recently had a client whose husband had two cell phones and was actively contacting two to three women at the same time. They all thought they alone were the object of his desire and they professed their "love" for him. Phone sex was frequent. When he needed a "new challenge" he would seek out another woman. He would "leave" one by not returning her phone calls).

There is often a progressive nature to the flow of "I Can't Say No." Sexual fantasites may lead to pornography collection or later obsession with pornographic material. Online relationships which may lead to clandestine meetings.

One grabbed by sexual addiction may move from pornography to strip clubs, to multiple partners and other forms of intense and/or dangerous sexual acting out.

There is a fear of being exposed, of getting caught. In the background is the knowledge that "getting caught" most likely will mean significant consequences for either/or his family, work and reputation.

There is the knawing fear that "something is not quite right with me." My obsession with sex is too much. I'm either not "wired" right or there is something wrong with me.

Shame and guilt are two underlying themes that perpetuate the hiding, denial and cement the seeming powerlessness over this force.

After the act (rendevouz, sexual release, etc.) s/he may feel terrible and promise to him/herself that, "That's it! I'm done. No more. I don't want to do this."

(If his/her spouse knows of the activity s/he promises to his/her spouse after the acting out episode that s/he will not do that again. This may be said with heart felt tears and remorse.)

However, such good intentions often fall prey to the power of his/her urge(s) and s/he acts out again (perhaps each time in a more destructive manner.)

One can readily observe a promise/failure cycle that ebbs and flows.

There is a"roller coaster" and succession of broken promises.

The "I Can't Say No" person has extreme difficulty forming a truly intimate relationship.

After all, to be in a truly intimate relationship means s/he must disclose some of his/her internal struggles and that often, to this person, seems beyond the realm of possiblity.

The confusion a child experiences in a home where sex is associated with abuse or extreme confusion, carries along with him/her that pain and confusion.

Future relationships become the testing ground to try out his/her attempts at somehow discovering the essence of his/her sexuality.

Often the original pain and confusion is played out in sexual relationshps within a marriage or in the case of someone who says, "I Can't say No" an extramarital affair (or string of them) or some other external form of sexual acting out.

Their world is perceived through the filters of their addiction or through the hold that sex has for them.

To defend themselves from the pain of their guilt, shame, pain and confusion they rationalize their behavior and discover ways of minimizing or explaining their rather odd persist sexual behavior to others, especially to those with whom they have an emotional investment.