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.