George Galloway's semi-recent statements on sexual etiquette are a great example of the shape of the line in the sand that I draw on offensive comments. I am anti-political correctness in the sense that I believe that people should not legally or socially be strongly nudged or required to care for the validation or feelings of belongingness of everyone in society, particularly those a bit off-the-beaten-path. I draw lines between toleration, acceptance, and validation, and comfortably place various groups into various categories and defend their placement differently.
I don't believe that rape jokes should be forbidden. In general, I believe that jokes should be permitted on any topic, and provided they're not normatively terrible, they're cool. We should be very reluctant to shove other people's expression around, particularly if and where that expression isn't meant to be normative (meaning pushing on societal norms). A number of authors and comics have deliberately made this their point, with either celebrated jokes like "The Aristocrats" or devotion to this kind of humour, like Sarah Silvermann, Frankie Boyle, and the like. All cool by me.
Galloway's comments are different. He made a serious statement that was meant as normative in a way that excuses a kind of rape. In contrast to humour, where normativity is not generally the point, and letting off unhealthy urges during laughter acts as therapy for society (Gilbert Gottfried has a great exploration of this in some of his more serious interviews), Galloway excuses a behaviour that should never be excused, denoting that kind of rape as "bad etiquette". By crossing that line, he becomes worthy of condemnation. Fortunately, he has been widely condemned for it, including from my fellow people who are worried about creeping-PC in our society.
Intentionality and normativity are the tools we use to demark what is acceptable and what is not. Nothing short nor far of them is acceptable; recognising too many harms as actionable mutes society, crippling its ability to have comfortable discourse. Recognising too few harms mutes real harms to people in society. (and yes, that word "real" there is meant with about as much nuance and force as you might imagine)
Let's remain comfortable with general expression among decent people, reluctant to criticise except when intent comes into play, but let's also be willing to intervene more forcefully and actually shun people who do more than imagined harm with their views. If George Galloway hadn't done enough harm over the years to make you angry at him, this last statement should've been enough.
(Note that I believe that couples may voluntarily, perhaps even implicitly establish norms for their relationship that permits the matter at hand, but that should not be taken for granted; Galloway's idea that permission flows from the relationship itself suggests that rape cannot happen in relationships)