What are the cheating guidelines?

I'm not so sure he has cheated at this point but it's probably inappropriate and unfair to you. Basically you treat your bf or gf the way you would want to be treated. You don't do anything that you need to do behind their back. You don't do anything that would hurt them. If you are doing something with another person that upsets your partner and you refuse to stop because it's more important that you do what you want rather than acknowledge their feelings, then it's wrong. Plenty of boys and girls talk to each other without raising the suspicion of their partners. Women usually can sense very quickly when somethings not kosher between their bf and another girl.