Nope. And assuming this is true is assuming all relationships are the same, which is kind of deppressing when you think about it. Some relationships are more casual than other, people are younger, more immature, etc.
My ex was actually married and had cheated on her husband before meeting me. But I didn't hold that against her. Only brought it up when she was acting holier-than-thou
That being said, someone MIGHT cheat repeatedly on all his/her partners because they end up with the same kind of person that "lack" something else they need. Until they find that right person, they might go on cheating. Or not.