Everyone is focusing on the political side of the question because he equated Christianity with Conservatism (big stretch).
But in reality, the question is more about Christianity, and it shows LM's ignorance of it. He assumes that all Christians are "Holier than thou" types. And sure there are plenty, but I doubt you'd find them here. But a more moderate interpretation of Christianity comes down the fact that we are human. And as humans, we are sinners. Period. And yes, we are told to abhor sin and live a sin-free life...but it's never going to happen, because we are human and therefore imperfect, and incapable, of being truly sinless. So that we will sin is a given.
More to the point, why do I choose to sin in this fashion? There are many reasons. But mostly it's from weakness. I'm not getting it at home. And I feel that, by being in the hobby, I can take care of my natural urges without the risk of becoming emotionally entangled. So while I may procreate with other women, I only truly love my wife. And I do. We are partners in every way, except one...sex. And I figured out a long time ago it's easier to get sex than it is someone who agrees on how to raise kids, how to manage fnances, how to run a household, how to argue without it turning into a Jerry Springer episode and so on. So I play on the side when I'm not getting any at home and I feel I'm able to be a better husband and father because I'm not pissed off because I'm frustrated.
Am I rationalizing my actions? Of course I am. Kind of hard to be overly critical of ourselves isn't it? But LM, the real question is, why the hell do you care? As others have pointed out, this is really just a leading question designed to allow you to "score points" with those you disagree with. What's the point in that? It comes down to this. No one here is above anyone else. No one is "right". There will ALWAYS be differences in opinions on things political. But you're not going to gain any high ground by wallowing in mud.
You wanted to know, so now you do. That's my story. I'm sure there are 100's of others, because we're individuals. And why any one person does a particular activity varies with the amount of participants, regardless of political leanings. But my guess is most married guys aren't going to take your bait. Number one, they have no incentive to do so. There life isn't going to be better for having answered you, and it could be considerably worse for having done so.