A few answers to the why-men-cheat question irk-me-the-fuck-out.
On the one hand, lack of effort on the woman's part:
"If you want to keep your husband sexually happy the best advice I can give you is, get the word “no” out of your vocabulary!" http://maggiemcneill.wordpress.com/2010/09/09/a-whore-in-the-bedroom/
On the other, that any extramarrital desire is sick and perverted - bad man bad.
Seriously, I don't think a wife should be a Stepford Wife and do all of the emotional and sexual work within a marriage. I also don't think a husband should be forced to remain monogamous or demonized if he strays.
Marriages fall apart due to poor communication and lack of compromise.
Primarily it is the former. What happens is that one party is not happy, something he does not try to change and does not bother to express to the other party; subsequently the other party becomes less happy, and it evolves into a decrepit spiral of misery.
I view this as a product of contemporary feminist dogma about gender equality. Particularly, second wave feminism
1) Declared male desire for sex as objectification and use of women, and made men ashamed of their own sexual desires.
2) Criticized little emotional or material motivators men have always used to get consensual sex.
3) Called women "repressed" and thus set the expected "bar" for sexual activity much higher.
4) Blanket-stigmatizing infidelity.
5) The Pure Relationship. Essentially, an idealized relationship freed from traditional economic and social constraints. A relationship that is only engaged in for what it can bring to both parties and that is reflexively evaluated - in other words: idealization of marriage and a structure in which failure of the marriage to live up to an ideal is a good excuse to break it...
As a result, men want and have gotten sex (prior to marriage) quite easily. Moreover, a variety of sex - oral, anal, porno-style, etc etc etc.
At the same time, once in marriage, men are ashamed of cajoling sex out of their wives, lest they be forcing their wives to engage in - oh no - unwanted consensual sex. They've also completely lost the art of cajoling unwanted into wanted.
They have also (because as we all know, masculine and feminine sexuality is essentially the same/gender is constructed) never been taught to engage in emotional work or honest, straightforward conversation about desire.
Thus - what happens?
Refer to the aforementioned spiral. Which typically ends with the sullen resolution that the marriage is bad, a series of affairs with secretaries/waitresses/strippers/housekeepers which either a) go no where "because of the kids" or (refer to the 'pure relationship' mentioned above, infidelity, lack of passion and excitement, and boredom indicates that something is broken. And interestingly, divorce is more socially acceptable than infidelity) b) lead to divorce.
Your wife works too. She is also primarily responsible for childcare and household work. She really does not have the time and energy to ensure that your pure relationship stays zesty, sexy and passionate.
You have to do some of the work. Here are a few simple steps to take if you are unhappy:
1) Take your wife out to dinner. Hire a baby sitter or leave the kids at your parent's house and fly your wife out to New York or London or where ever you're traveling to. Do exactly what you would do with a call girl, except only with your wife (seriously, it will be cheaper.) I'm overworked, stressed constantly, etc. etc. etc. But still, it only takes the right kind of affection: listening to me ramble, little pats and cuddles and kisses, a thoughtful gift, a little love note, a dinner cooked for me, etc. etc. etc. and I'm more than in the mood.Even something a wee bit exciting. A note left on her dresser or a piece of lingerie. Essentially, all you have to do is demonstrate clearly that you passionately desire her.
2) If your wife is still sullen/cranky/whatever, talk. Talk about problems you are having/things you want that aren't there. Ask what problems she is having/things that aren't there.
3) If there are certain types of sex/fantasies she isn't into...or vice versa, talk about whether or not she would be comfortable with you getting them outside of the relationship. Establish rules. Make it explicitly clear that you are still in love with her - that it's just an excitement thing (seriously, I don't think I'd be able to keep up excitement/passion in a long-term monogamous relationship. And I do think infidelity - FOR BOTH PARTIES - stirs up an appreciation for the stability, friendship, and love in a long-term relationship. And I also do think that there are some things you can get from an escort that I would not want to give my husband. I would not want to perform porno-sex. I don't think I'd want to dominate my husband or be dominated by him...simply because I'd worry that that dynamic might seep into the overall relationship. I would be happy to pleasure my husband; but while I can fake it for cash, I simply cannot fake it for love).
Possibly purchase the 1970s "Open Marriage."
Establish rules. Maybe offer up a my-fault-you-take-95%-of-our-net-worth contract on the off-chance you fall in love in your dabblings and they detract from the marriage. (If my husband mentioned this, I would be way over okay with him doing whatever he wanted. I would be okay with not because of the insurance; right - the insurance would make me less used or cheated if he left me for someone half my age; but more importantly, that declaration would be an expression that he doesn't want anything beyond physicality; and more importantly, a built in incentive to just not let emotions develop.)
Honestly encourage her to express any sexual fantasies she has which are extra-relational. Maybe she just wants to be taken out to dinner by another married man on a "casual encounters" website. Maybe she wants to work as dominatrix or an escort. Maybe she wants to be gang-banged. Whatever. You have to be okay with that too.
4) If this fails, then you have my blessing to do whoever the fuck you want.
p.s. This whole post is based in my personal belief on gender. I think that men and women do experience sex differently and that masculine and feminine desire is different. I think this is inextricably tied to the dynamic of heterosexual intercourse: a man is doing something to a woman (Being on top is sort of like moving the wood-barrel of milk rather than the churn...get what I'm saying?)
However, I do not believe not for one second, that men are fundamentally incapable of engaging in emotional work or communicating.