And the husband hasn't been able to see his toes for years.

I would say that it would emanate with the lack of attention that a partner is not receiving.  After you get past all of that and lack of interest, then it would be specific things within the relationship such as sex or more specifically oral sex.  The question is what are the participants in the relationship doing to keep it interesting. Also in this case, was oral sex a deal breaker during the dating process as it has become during the marriage.  Once people needs are not met in the primary relationship then they go elsewhere to get those needs fulfilled.

A good lickin' will keep me cumming back for more..

There leaves a lot of question on this particular study. I cannot say if it is objective or suggestive. I am not married and hardly have ever had a problem with my partners in the past with oral sex. I love oral sex from giving to receiving. The real issue that seems to be a common dominator is communication & attention or lack there of attention. I am only speaking from my own personal studies and life experience. EOM

I think lack of oral is a result of  animosity  building up. If you are or your partner starts to feel that way irs doubtful a no or daty is coming. My ex built up resentment to me. Cut off Bus (which she wasn't very enthusiastic about to begin with) and then cut off daty. Dumb fuck that I am I didn't know the end was near. Lol

...that a high percentage of couples might look elsewhere due to lack of oral sex. I might be weird, but I would choose fellatio over vaginal intercourse any day if I am forced to pick only one. Since my name isn't Steve Bannon, I need someone else...

Yes Great Blow jobs and little Kisses All Over, is the answer

Oral is great, but companionship is too .. Live Love & Laugh...

I love oral. Actually more giving than receiving.

Been married 37 years. Wife offers oral sex on Birthdays (40th Birthday to be exact).
And never liked receiving,  
(No lectures on why we stayed married. I have heard it all. Suffice to say there is more to marriage than sex).

It is not my technique, I am excellent at it. I have made several woman squirt for the first time doing this.

This hobby has saved my sanity.  Gives me a great outlet without having to break up a family.

I would just add, that from my experience, lack of oral sex is a prelude to a lack of interest in sex at all.

Married 25 years and the sex has stopped. Oral consists of my wife licking the tip of my dick while she give me a hand job. As far as going down on her - she does not want it and has a dozen excuses why.  

While writing this I am planning my next tryst with my favorite provider.

I did say can be. My experience with women in my life has been that some women lose sexual desire and some gain desire with the onset of menopause. I'm not a medical professional, but I've been married to two women who have gone through it.

Along with sexual desire going, other personality changes occur with the brain chemistry. I didn't cheat, I left.  

At my age, the  only thing more boring than sex with someone not interested,  but doing it out of duty is........  well not very much.

It's just the progression of humans being.

When my ex abruptly moved out I saw a female therapist. She said she saw around 5 men per week in their 50s that were in my situation.  
She felt bad for the men. She said ladies remember everything the spkuse didno matter how small.  This leads to a mountain of resentment and the sex stops. She said the wife then goes through menopause and she may not have a perfect life and boom. Its over. Makes marriage sound stupid.
And now I'm stuck with a mindset where I couldn't imagine being with a lady my age. Damn hot 20 somethings.😁

It could be fear that  putting a cock into her mouth might be too risky. What if she got hungry?