Obviously this is an individual issue for some people, and not an issue for others.  I can make broad sweeping statements in response but they won't be right for everyone, but there are several issues that really seem to pop related to this problem.

1.  Why are they desiring the 20 somethings instead of their own wife?

2.  Do they understand what it is that makes their wife feel loved?

3.  Are they expecting her to take the initiative?

4.  Are they communicating their needs to their wives, and more importantly, listening to their wives' needs and fulfilling them?

Basically, they most likely need to man up.  That doesn't mean forcing sex on your wife.  It means ignoring the 20 somethings and focusing on your wife, it means putting her needs ahead of your own, it means taking the initiative to communicate (ask about what she needs FIRST!) and remembering that you are tied to this person, to be closer to this person than any other person for the rest of your life.  Start acting like it. 

If there are kids in the picture, sometimes women feel weird about sex with kids in the house, or at least more inhibited.  Be willing to put a lock on the door or whatever it is you need to make her feel safe.

And, maybe perhaps most important of all, is love and be there for your children.  How can you expect a woman to respect you if you don't take care of, and love, your children together as much as she does?

Maybe they are wimps, but not in the way it read here.  A wimp is the guy who wants the benefits without the responsibilities.  A real man takes responsibility, leads courageously, rejects passivity, and expects the reward for it all in the afterlife, not in the present life.

Thanks for the article!

The problem is that it always seems to be the men who need to make an effort 'understanding their wife', 'listening to her needs', 'taking the initiative'. It's like if you visit a dating site. Women's profiles are really amusing in my opinion - large (let's be honest and write it, 'fat') women describe themselves as 'cuddly', 'a few extra pounds' and the like and they more often than not state that they 'only' want someone to 'make them happy', to make them 'laugh', a 'shoulder to cry on', a 'tall, dark and handsome stranger'.

Of course I am ignoring the counter argument that men on such sites will post the most flattering picture, describe themselves as 'stocky' when they mean overweight and are often looking for women they would describe as 'sexy' but I do think that there is a convention in society that it is a man's job to understand, anticipate, treasure, listen, support and basically be the one who has to be the grown up. And they need to do all of this if they are to be 'treated' to sex.

Whereas, my friends dating younger women seem to have no such obligations. These younger women have no hang ups about being treated differently, they enjoy and want sex just as much as the guy and they are happy to make the moves. Is the problem a biological one - women change as they age and don't want or need sex, a societal one i.e. society is different now and so women are different, an attitude one i.e. young women are more open to new experiences and have grown up with a more open view of the sex act? or something else entirely? Perhaps it's just my male friends who are experiencing this problem. I guess I will have to suggest they read Cosmo for some tips on 'understanding the older woman' because they seem to understand the younger ones well enough!

Blame all your problems on the disordered roles, values and mores of Secular and Atheistic Humanism, Radical Feminism and the Sexual Revolution.

Despite the fact that most of human history has men in charge, this is not the 'natural' state of human relationships

I think the inequality of the male female relationship has a very primeval foundation to it.... in biological terms human beings are fundamentally wired by nature that the female is the chooser. Males that fail to please, well, they get the boot!

EDIT: as for all the rest of the stuff that goes wrong in relationships, well i blame most of that on modern schooling... as opposed to olden day schooling with 'the strap' and the teaching of 'respect' and 'discipline' which are both invaluable tools for successful relationships.

Observation of people and observation of nature