As a marriage counselor in Denver, I have worked with hundreds (if not thousands) of couples over the years. One of the more common reasons couples come to me is because one of the spouses stepped out on his or her partner and had an affair. One of the most common questions I hear when a wife finds out that her husband cheated is, "why?"

Well, after several years of helping couples recover from affairs, here are nine of the most common reasons men cheat.

1. No Romance

Marriage is supposed to be passionate and romantic. Unfortunately, many women fall victim to the "Prince Charming Fallacy," believing their husbands are supposed to be the ones romancing them and that they don't need to romance their husbands in return. Well, after several years, some men just get tired of being the only ones trying to create romance, and they step out to find it elsewhere.

2. No Intimacy

This one is cliché, but it's also true. Many men get married, expecting to have wonderful intimate relationships with their wives. But they may find that their sex lives are lacking - or nonexistent. Because intimacy is an important part of being human, some men seek outside their marriages to fulfill those needs.

3. No Love

Men don't just have physical needs. They need love, too. They want to feel cared for. They want to feel like they'll be missed if they're gone. When men don't feel loved, some choose to turn away from their marriages and find love with someone else.

4. Emasculation

Just like many women like cute outfits and crafting, many men like watching football or playing cards with friends. After marriage, however, many men feel they can't express their manly sides without criticism from their wives. After years of being emasculated like this, they find someone else who will accept them for who they are, and betrayal ensues.

5. Life Changes

People change. They're supposed to. You don't want your 50-year-old spouse to act like he's 20. Unfortunately, you can't predict all the many ways a person may change in his lifetime. You can't even predict all the ways you will change. So, as some men grow, they may realize they aren't as happy with their lives as they would like to be and make drastic changes (i.e., begin an affair).

6. False beliefs of Manliness

Growing up, boys see TV shows where the "cool guy" gets all the girls. They see the popular guy in school get crowned prom king with a gorgeous prom queen by his side. As a result, many men erroneously believe that, in order to be real men, they have to be able to get girls. They try continuously to push the line by being flirty and assertive with women. But, when men push the line for too long, they eventually cross over it, and infidelity occurs.

7. Tired of the Same Old Routine

Humans need novelty. They need to constantly stretch themselves and grow. Unfortunately, a lot of times in life, people find themselves feeling unchallenged and bored - tired of the same old routine. Some men step out of their routines for extra novelty and excitement.

8. Tired of Being Nagged

Women are generally more meticulous than men. For example, women are much more likely to use a specific sponge for the dishes and an entirely separate sponge for the counters, but men use the same sponge for both. Instead of appreciating these differences, some women complain about them. When a husband (or anyone for that matter) feels like he's always being criticized and unappreciated, he may choose to look outside existing relationships for appreciation.

9. Dissatisfaction

This one just about sums it all up. Some men cheat - even if they're happy with their wives - because there are vulnerabilities in their relationships. These vulnerabilities are very often some form of dissatisfaction - emotional, practical, intimate, etc.

While many of these reasons point toward a wife's flaws, it's important to understand that a husband's cheating isn't his wife's fault. While many men may blame their partners, a husband obviously plays his own part in his poor marriage, and he needs to identify his role in allowing the relationship to deteriorate. He also needs to identify why he allowed himself to have an affair instead of choosing a host of other options available to cope with an unhappy marriage. Together, couples can rebuild their relationships to be happier and stronger than before.