1. Going Through A Transition

"If it is graduating, turning a certain age, losing a parent or advancing the relationship status, women become introspective," explains Lee. "Even if it is something she wants, such as just getting engaged or graduating, the transition can stir up an array of emotions about where her life is going or where she is in it. The discomfort of change can trigger an impulsive desire to find someone to take her focus off the change and be a diversion for what she is going through."

2. Not Feeling Adequately Celebrated

We've all been here: "May it be getting a promotion, organizing a fundraiser, or making Thanksgiving dinner for a party of 20, men often make the misstep of "not complimenting their partner's achievements," Lee says. "Women seek an emotional connection that their partner notices them, is proud of their achievements, and appreciates what they do, so when they aren't getting this at home the residual effects lead to feelings of frustration, dissatisfaction, depression, and restlessness."

And that's when they could go looking for it elsewhere. "When you are living in the day to day with someone, it is challenging to step outside a situation and notice the things that do matter to someone," adds Lee "As this wears down over time, so as soon as the woman encounters someone who ignites the spark they are lacking at home, they equate it to an emotional connection and seek companionship with someone else."

3. Feeling A Relationship Ending

"When a woman feels that uneasy sense that a relationship is on the outs, by either her doing or his, she will often look to fill the void externally to soften the blow," Lee reasons for a woman's infidelity. "If she is the one considering the breakup, she may be using this tactic as a challenge to herself both testing the waters, and then gauge if she can go through with it."

4. It's Just Not Fun Anymore

...But it's too hard to pull the plug. "When you don't laugh, you don't love. Laughter is one of the key elements in a relationship that often gets overlooked," Lee explains, simply. "When stresses of day to day life become the dominant factor in a relationship, women feel unhappy. When they come across a coworker, or friend that they have a good time with, it suddenly brings to light what is missing in their own relationship and becomes tempting to act upon."

5. It's Boring In The Bedroom

Men aren't the only ones who need to spice things up. "Women need to feel desired!" Lee declares. "If she is not getting any, enough, or nothing to talk about, women start to feel a sexual void. With the popularity of books such as Fifty Shades of Grey, television shows, or listening to friends talk about their fun single trysts, women have that moment when they compare their love life at home to what the rest of the world seems to be experiencing." And that's when she may start to wonder what she's missing.

"Though it is easy to pinpoint the flaws in one's sex life, it is often hard to make the changes needed to correct them," adds Lee. "This creates a temptation in women to seek sexual satisfaction elsewhere with someone they don't have the baggage with and can be more uninhibited."

Now you know why women cheat. But we say, if you're thinking about cheating, just break up with the guy, before you move on to a new one.

说到男性，大多数人都会觉得他们骨子里是欲望动物：眼神游离不定，还想要拥有多位性伴侣。但是，说到出轨，也许男女比我们想象得更加“平等”。（比如克里斯汀?斯图尔特）心理学硕士、两性关系导师蕾妮-李给出了以下5个女性出轨的理由。

1、正在经历转变

“如果正面临毕业，到了某个年纪，失去至亲或感情状态更进一步，女性会开始反思自己。”蕾妮解释道，“即使这些是她想要的，比如订婚或者毕业，但这些转变还是会在内心激起波澜，她们不禁会思考应该何去何从，或者她自身的状态。这些变化带来的不快会使人一时冲动去另寻他人来分散自己的注意力，让自己暂时逃避目前的处境。”

2、觉得不够被重视

我们都有过这样的情况：“工作上得到晋升，组织了一次募捐活动，又或者给20人聚会准备感恩节晚餐，男性常忽略的一点是：没有好好赞扬妻子的成就。”蕾妮说，“女性总是希望她们的丈夫能给予她们更多关注，为她们的成就而自豪，并感谢她们的付出。所以，当她们在家里得不到这些情感需求时，她们会觉得受挫、不满、沮丧、不安。”

这时候她们就可能会另寻关心。“当你日复一日地和另一半一起生活后，经常会忽视掉对另一半真正重要的事情。”蕾妮补充道，“随着时间的流逝，一旦女性此时遇到一个可以弥补这些的男性，她们就会视之为感情，进而想和对方进一步发展关系。”

3、觉得感情关系走到尽头

“当一个女性觉得这段感情快要枯萎，不管是自己还是对方所致，她可能会向外寻求慰藉来填补目前的空虚，使自己不至于受到太严重的打击。”蕾妮在分析女性的背叛时，认为“如果她是那个想要分手的人，那她可能会用这种策略来挑战自己同时探探风头，然后寻思是否能这样做。”

4、生活没有欢乐

...但却很难停下来。“当你们之间没有了笑声，没有了爱……欢笑是一段关系中很重要的元素，但却经常被忽略。”蕾妮简单地解释道。“当紧张压抑成为每天的主旋律时，女方会觉得不开心。当她们遇到一位可以共度美好时光的同事或朋友时，她们会突然发现这正是目前的感情关系里所没有的，因而会甘愿冒险。”

5、床上生活较枯燥。

并不是只有男性需要调动情趣。“女性也需要得到满足。”蕾妮声称，“如果她的需求得不到满足，女性会开始感到性空虚。”在女性阅读《五十度灰》等热门书籍、观看电视节目、或听朋友聊单独约会的乐趣时，会将自己的爱情生活和其他人相比较。”蕾妮补充道，“这个时候她会想想自己错过了什么。”

“尽管很容易就可以找出性生活方面的不足之处，但想要改正过来却有些难。”蕾妮补充道，“这会诱使一些女性出去另寻无拘无束的性满足。”