What do you think about someone who cheats? Do you believe the saying "once a cheater always a cheater" is true?
I don't think absolute statements like "once a cheater, always a cheater" are true. If you can see how cheating involves certain thoughts, patterns, and acceptable norms, then changing those thoughts, patterns and norms would change the cheating behavior. To do that, you have to understand their architecture.
There are, I'm sure, lots of reasons people cheat. Some might see it as a natural part of a relationship. Others might use it as a tool to exact revenge on their partner. Still others might resort to cheating to sooth their loneliness. Whatever the reason, cheating, like all sex, has addictive properties that make it hard to change; sex, flirting, and feeling attracted to someone are all stimulating and addictive.
All those cognitions and behaviors can be changed, but you need something really impacting to do it, especially since they're locked in with addiction. Overwhelming guilt, deep self-reflection, illness, or some other kind of crisis might have that effect. I'm not sure it's the kind of thing you can change in another person, but I'm sure it's the kind of thing you can change in yourself if you were inspired to.
I don't want to judge cheaters, but I think they'd be be happier if they didn't cheat, even it meant ending their primary relationship. You can't really care for a person when you cheat behind their back and violate their trust, so cheating complicates things rather than resolving them. Also, cheating cuts you off from your conscience, a connection that I believe is the key to deep happiness.
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