What makes people do others dirty?

So, why do people think it is ok to do others wrong? I for one believe that God has a way of dishing out dirt to those of us that do like to do things like cheat on a spouse or steal money or whatever. It may not be right away but somewhere down the line it will happen. I’ll give you an example, I was dating a girl for a couple years and she cheated on  me. I was upset of course but guess what happened….she got pregnant and married a guy based off of that reason. Is she happy? maybe? but she was only 21 when it happened. That means her whole life no revolves around that kid.  Yes, kids are a gift from God but Im sure she was hoping to be a little older to have kids. Now, I get phone calls from her telling me how she cant bond with her husband like she did with me. I think that people that cheat are weak and pathetic! Have you ever been cheated on before? How did you handle it? Or are you the cheater? tell us why you cheated and see if you can truely justify it.