What is cheating? Is cheating the actual physical act of having sex with someone other than your committed partner?

It is more likely that the actual physical act is only the confirmation, the external representation, of the mindset which would allow it.

Perhaps the word infidelity would be better suited for this idea. Cheating has a physical connotation which does not truly represent its nature. Infidelity is broader and more encompassing, and allows the inclusion of mentality into the context in which it is used. When you see the word cheating, think of infidelity instead.

The bond which holds two people together is strongest when there is a mental barrier to the idea of cheating. Once this bond has been stretched, it is easier to break. A person is most committed to another person when that bond is strongest - that is, the idea of cheating does not even exist.

It would be unnatural to think that when a person is committed to one other person, they will not be attracted to anyone else. This is a natural process and should not be discouraged. But to allow oneself the indulgence of consciously carrying that thought to other conclusions (i.e., "I wonder what she's like in bed?") will cause a stress on the bond that holds these two people together.

Would you put a picture of a nude model next to the head of your lover to look at while you were engaged in the act of sex? Why not? Because while you would be having sex with your partner, you would be thinking of someone else, which is universally discouraged. Calling out the name of someone else in bed is embarrassing, to say the least. Why? Because it reveals that you are thinking of someone other than your lover. And this is, albeit less egregious than the physical act, still cheating.

Sex is a state of mind as much as it is a state of body. It requires an active participation of the consciousness of the people involved. Cheating must happen first mentally before it happens physically. How many times have you had sober sex without at least wondering what the other person was like before performing the actual act? This procession to physical from mental is all part of sex in any form - oral, intercourse, or cyber.

So it is not the actual physical act of intercourse that denotes infidelity (cheating); it is only the most obviously manifested sign. Cheating begins in the mind. Cheating can be entirely performed in the mind, though to a slightly lesser degree. It does not require any form of sex to be unfaithful.

If your partner is having cybersex with someone else, they are being unfaithful to you. The bond that you share will be weakened simply by the decision to share their most intimate thoughts and desires with a person other than you. And unwillingness or inability to stop only shows that they do not respect you enough to stay faithful to you. So is cybersex cheating? Absolutely.