The person being offended is the one that defines this of course. How can you offend yourself? For example. I say "hey woman this is the deal". The woman in turn asks me not to speak to her in that manner. Has nothing to do with the weight of the argument. Its only concerning the manner in which the information is exchanged. If I cant become PC and respect her wishes I just cut off communication. I may walk away feeling as if I "won" something but I have actually lost more. All I have really done is self validate my beliefs instead of learning something.
You are confusing PC with etiquette. Today's PC jumps to minutia, about what pronoun you are supposed to use, and if you use the wrong one, how much of an offense that is. It's gotten to the point where having the last name "Lynch" and having as the name of a Stadium is somehow offensive. In your example, you are not being un-PC, you are being uncouth, and there is a difference.
PC is not the same as etiquette. I'm using this definition.
politically correct
adjective
1.
demonstrating progressive ideals, esp by avoiding vocabulary that is considered offensive, discriminatory, or judgmental, esp concerning race and gender PC
That is the facade of PC, and back in the 90's it was what was considered PC. It was the show you put on to imply you were "right thinking" on various topics, which again leads us down the path to the goal of PC, not the show of PC, the goal being avoiding discussion on topics you disagree with, not engaging in said discussion.
Today, the definition of what is offensive has been expanded so greatly that it exposes the true reason behind PC, which is Idea control, not Language control.
When every phrase, term or saying that explains a position you don't like is considered offensive, then again, the true reason behind the whole PC/SJW/Micro-agression thing becomes clear.