Do you think once a cheater always a cheater, or do you think they can actually change?

I think that cheating is a result of deep selfishness. Selfish people aren't prone to changing for the better because they don't see anything wrong with how they are. The people who take them back fuel this delusion because they erase the only thing that could possibly make a cheater change which is the consequences of their actions. Cheaters only change when they face the negative consequences of cheating. This means that the best chance a cheater has to change is to stop dating until they confront the psychological issues that have led to this self and community destructive behaviour.