As humans we are creatures of habit. We have the certain things we do, we get bored, change it up a bit, and more than likely go back to our old ways because it’s what we feel as “comfortable.”
People are predictable. Your body functions a certain way because of the needs and wants that it craves. Think of it this way: we are creatures of habit. We need food and water to survive and when we don’t have it we fight for it. Our body goes into starvation mode and we will do whatever it takes to get it. Personalities are the same way, only that the things we long for we don’t necessarily “need” we just “want” them. People are used to having things like affection, alone time, human interaction, and sex. If they go without having it for a while they have withdrawals and look for ways to have them again.
The most common scenario that I’ve recognized with men and women is the sex issue. Men crave sex more than women typically do because they think that they “need” it. They actually just “want” it from a result of being more visual. The thought of males needing to “spread their seed” is a little misleading. I believe that men actually do this out of dominance and not just because they feel the need to spread anything…especially STDs. Men tend to feel more powerful and a bit domineering when having sex with a woman. Most men feel a sense of pride after they engage in it; women on the other hand feel the opposite. A study done by Neil Rose, a marketing professor at the Northwestern University of Chicago, showed that after surveying 370 adults aged 20 to 80 across the United States asking what they’re biggest regret was. For women 44% of it was sex and for men 19% of it was sex. The men’s biggest regrets came from work-related issues.
Why is it that women regret sex more than men? Women are mental analysts. Think of it this way, when a man thinks, he is able to concentrate on one thing at a time. Sports: he is watching the game and if you are talking to him he will have to pause to be able to listen to you and enjoy the game at the same time. Women on the other hand, their mind is like a honey comb. All those little compartments are constantly filled with little bits of information, weaving around their mind at the same time. Women can do more than one thing at once. We are pretty talented, juggling babies on our hips, cooking dinner, and talking on the phone all at one time. It’s what we are wired to do. Because women connect intellectually, they often regret one-night stands because it makes them feel less powerful, like they have been dominated in a way. Men see what they want and they go for it. They are the hunters wanting the prey. They will do whatever it takes to get what they want. Women are natural gatherers. They gather information from all aspects and analyze it before making a final decision. One-night stands do not give them enough time to decipher a good or bad decision, not saying that some women don’t want a get-a-way for a night.

To get what you want you have to break habits. People become too comfortable with routine and it becomes too easy. If you want to be with a faithful woman, you have to be a faithful man and give up your side job. Same goes for women. It would be blanket advice for me to say that this happens to "everyone." This happens to some people, more than I'd like, and I see them hurt. It's sad, but to get what you want you have to break habits and do what's best for yourself. The devil is in the details so look at the big picture ladies.
*Thank you Michelle for inspiring me to write this :) I hope you figure out what's best for yourself!