Definition of cheating will vary widely - depending on whether you are conservative, open minded, secure or insecure, or a plain swinger.
However IMO - In normal circumstances, once in a committed relationship, any emotional/intimate/physical interest in a member of the opposite sex (and in some cases, same sex) would qualify for cheating. My idea/guage is, dont poke where you wont like your partner to be poking.
I believe you're on a roll here...BonBon agrees with you one more time!!!!!!