Men and women have different point of views in terms of what's considered cheating. Let's review. We will start with men, being the list is much shorter.
Men: Cheating is the following (I am answering for heterosexual males here)
*Sleeping with another man is considered cheating.
*Oral sex with another man.
Men: What is not considered cheating:
*Sleeping with another female
*Talking to another man (co-worker, friend, classmate)
*Meeting another man for lunch for business
Women: Cheating is the following
*Sleeping with another woman
* Oral sex with another woman
*Talking with another woman
*Emailing another woman
*Business luncheon with another woman
*The neighbor that is overly flirty
* The young waitress
*Anyone that is perceived as younger, smarter or a better body than your current spouse, g/f, partner, significant other.
*Any contact in your phone that we don't recognize as friend or family
*The new Facebook friend that was just added
*Hell, even your second cousin that is hot
If you have been cheated on, it does not matter which sex you are, you want to know why and how?
The emotional response is usually the same. The grieving process then begins for your relationship. The relationship will experience trust issues as well. Denial, anger/rage and then acceptance are soon to follow after the infidelity has been uncovered.