I don't believe it at all. A man who cheats is focusing on his own wants, needs, and desires. Such a man is selfish beyond words. If a man really loves and cares for his wife or girfriend, he WILL NOT cheat.
Sure they can, and oftentimes they do still love the person they're with. Such men are indeed selfish beyond words, but that doesn't mean he doesn't love his SO, it simply means that he's self-absorbed enough to think he won't get caught, hence, he will never lose the one he loves.