Roman Was Recently Chatting with Someone Online and the Conversation

Roman was recently chatting with someone online and the conversation got very sexual. His current partner found the conversation and got very upset with him. They had explicitly set out rules for what was acceptable and not in their relationship when the other person was online. What principles did Roman fail to follow?

A) Rules of fidelity
B) Proper netiquette
C) The "green-eyed monster"
D) All of the above