Picture this: You enter a house and the walls are painted a musty yellow, there is water damage, it's cracked, and parts of it are fading to brown. But, in your hand, you have beautiful... wallpaper! No one ever has to know that thin paper is the only thing separating them from something ugly; just move on and cover it up.
This seems to be a trend in relationships. One way people try to "move on" is by getting into another relationship. They feel that they can cover up the mess of their past relationship with a new one – one that will look perfect on the outside. However, what they tend to forget is that their "wallpaper" may start having the wall underneath show through. All the nastiness, distrust, lying and self-doubt is brought to the surface and corrupts another relationship. Nothing was ever resolved from the past relationship, you just simply paste over it because you didn't want to have to look at it any longer.
You have to put in a little work before getting into another relationship, and things will get messy. A lot needs to be done before you move on, from scraping off the paint to patching up the wall. When you acknowledge the downfalls of your last relationship and come to terms with it, the result is a relationship better than the last, because you learned what went wrong in the last one instead of just hiding it away.
In addition, don't be hasty to get into another relationship even if your ex is in one. Sometimes it feels as if people can move on easier than us. However, you have to heal in your own way, not according to how others do so. Consider it like this: You could hire the teenage boy down the street to put up your wallpaper. He would say sure and would work quickly, pasting up the wallpaper half-hazardly. Or, you could hire a professional. They would come in and remark that some work needs to be done in order to fix the wall the right way. However, by hiring a professional you know that in the long run it was the better decision; it wasn't a "quick fix."
Don't have a "quick fix" relationship. Come to terms with the last one and give yourself time to heal. If you do this, I promise the wall will be stunning on the surface and underneath.