1. His insecurities.

He was jealous and always worried about the extent of your relationships with other people. He worried about your male co-workers, old friends and even the male waiter at the restaurant you guys dined in. He simply felt he wasn't good enough for you and you'd eventually find a better catch and dump him!

2. "You" were too clingy.

You constantly called or texted his phone when you guys were away from each other. You required his attention all of the time. You hugged and kissed him every second you guys spent together. He felt smothered because you went absolutely everywhere with him and gave him no space to breathe.

3. "You" got comfortable.

Before you guys got serious, you wouldn't dare let him see you without your makeup or hair done. Now you walk around him completely comfortable with a mud mask and a scarf. You stopped being spontaneous and dressing sexy for him.

4. He felt unappreciated.

He didn't feel needed or appreciated. A man's job is to provide and protect. He needed to feel his contributions and efforts were getting noticed. You didn't realize he needed affirmation and praise for all he does. How could he have known he was pleasing you and making you happy if you didn't tell him?

5. He was just a cheater.

Cheating for him was exciting, sporadic and fun because he simply liked to cheat. He did it before and got away with it. Once a cheater, always a cheater. He will never change because cheating is like basketball for him and when he plays, the ball stays in his court!