What is cheating? Who define cheating? Explaination stated in dictionary as follow: To deceive by trickery. Everyone understands?
When 2 persons involve in a relationship, If your mind is thinking of someone but you are in a relationship with another, is this consider cheating? To my opinion, that is cheating........... emotionally. As long as you don't spill the beans out, no one will know, so who cares? But when this progressively become a catalyst to break up a so called "problematic" relationship. What is that then? Jumping into someone's arms when you are in a "rebound" state. I bet friends will start to used names such as bastard, slut, bitch, asshole.. etc... for those who initiate the break up. Yes....I know its unfair and its none of their business. Mouth is on their head, what can you do?
In a woman point of view, as long as a man is thinking of some other women, he IS cheating. It is a known fact that couples will have crushes on other people (on and off). To all the men out there, its better not to say it out! Unless, you want a big fight to "spice" up your relationship. To a man, as long as they have not slept with the girl, they are not cheating, even if they have kissed them. To me, always be fair, if a man wants to have someone out there, allow your girl to do the same thing.
Ultimately, there is no right or wrong in relationship. Don't get too affected about what other people say because there are only 2 persons involved. Just try to consider how the other party feel. Afterall, it maybe a vicious cycle!