Heheh,..I knocked it out with my wife of 14 years last night and it was great.
I realize my marriage is an exception to the rule, but what your friends are relating is true. I've yet to meet the married man who told me he's getting more intense, more frequent sex after marriage than when he was single (myself included).
The problem boils down to this; people subscribe to popularized myths about how life after marriage "usually plays out." What I mean is that there are a whole slew of social conventions and myths fueled by pop culture media that feed into all these rationalizations and excuses for getting comfortable, losing your edge, letting yourself go, etc.
For example, women, especially ones who struggled with maintaining their body image while single, are only too happy to buy into the socially reinforced notion that a woman is going to unavoidably "put on a few pounds" (more like 30 - 40lbs) after marriage, and her "body will never be the same after childbirth - evil 'shallow' men just don't understand." And men of course are encouraged to accept this at the risk of being shamed by the same social convention. The
expectation then becomes one where she's predisposed to accepting herself becoming fat.
Men have their own set of post-marriage social conventions as well. He's supposed to be improving his lot in life and becoming a better able provider, irrespective of career or personal choices, or circumstances beyond his control. If he was an AFC prior to marriage, the associated ideologies and behaviors then carry over into his own self-expectations and his readiness to compromise and excuse his wife's rationalizations - though privately he'll grind his teeth about it. He is stuck with the the knowledge that, barring infidelity and shame, his wife is the sole arbiter of his sexuality and he's forced to play by her rules of rationing sex for him.
Now add to all this that familiarity is anti-seductive. Most married men will never be in a position to restoke the competition anxiety and excitement that made them attractive to their wives while single. The average married man is often too busy or too deeply invested psychologically in his own social conventions to ever challenge himself in questioning how he came to be in the position he is, much less attempt to come up with ways to prompt his wife sexually that might rock the comfort boat and have her withhold sex even more. Married guys wont risk shaking up their wives by experimenting with ways they think would upset the mediocre flow of sex they do happen to get.
At this point in my life I'm in a very unique position for a married man of 42. I work in an industry (liquor) where I'm around beautiful younger women on a weekly basis. I'm in peak physical condition, and my job is such that I have demonstrably high status. My wife knows I have game and I use it, on her and at work - even with our daughter when appropriate. She's always known I have an impossibly high physical standard for women, and I've had "a lot of girlfriends" in my past. I travel frequently and have any number of opportunities to hook up if I chose. The competition anxiety is ever present.
To the average married woman (and far too many feminized husbands) all of this may sound like a recipe for insecurity and neurosis for my wife - nothing could be further from the truth. Women don't want a man to cheat, but they love a man who could cheat. That's the DHV element that is severely lacking in most marriages. What's ironic is that most men wouldn't need to turn into James Bond to achieve setting DHV (demonstrating higher value) with their wives. Women are very perceptive of subtle changes, and often this is enough to trigger a husband's (and DJ's) most valuable tool - her
imagination. Just getting in shape or prioritizing yourself before her are enough to get the hamster wheel spinning in her head. Humans are creatures of habit with an insatiable need to see familiarity in other people's actions. Your predictability gives her a sense of control.
After 15 years, I still want to bang my wife, and as often as opportunity (not convenience) permits. How many husbands can say that? We don't have sex as often as we did when single, or as often as I'd like ideally, but I still do enjoy Mrs. Tomassi's body when we do. It is entirely possible to achieve this, but the seeds for it are sown BEFORE you get married. If you enter marriage as an AFC or with her controlling the frame you'll spend a good portion of your marriage fighting to re-establish that frame; and that's assuming a guy can unplug and come to terms with his own AFCness.