How do I know if he's cheating on me?

Just an observation about the post that mentioned at first they might go on about how much they do NOT like the other person. I have found this to be true. Often when someone is attracted to someone they can try and not like the person by trying to convince themselves and those around them just how undesriable they really are. You 'feel' it in your heart. But you KNOW it in your spirt. Ask him and look in his eyes, you know when he's lieing. I agree, we do 'feel' it...our 'gut feel' really works...we get this nagging feeling that something is not right, or unusual...you see this in his many actions. He would talk about an officemate...first he would criticize her, like how bad her hairdo is, how she looks and walks like a man or a horse, how very few friends she has in the office, how she could dare to go somewhere alone without her family...then later on he would appreciate her, like how good she did in her tasks, how fair her complexion is, how good a wife she is to her husband (yes, if she's married!), that despite the fact that he knew she kicks her daughter when she's angry and how impolite her children are!...later on you would catch some text messages between the two of them which are not like the types a boss would send to or receive from his employee. You would 'feel' that something so unofficial is going on between the two of them. You would listen to brief conversations on the phone and hear how sweetly he calls her name and how low his voice would be. He would keep his phone inside his pocket all the time, or with him inside the bathroom when he takes showers--when he used to just leave it around, now he keeps it! Then you would then hear from other people that the two of them are spending much time with each other in the office, oblivious to many people walking in and out or pass them. Change in lifestyle, yes, he becomes conscious of his looks and his clothes and you get to learn from the girl that they share the same health regimen..oh, it goes on and on and on...he may deny it and even fly in rage that you're "accusing" him of it...but what is in your heart?