Different strokes for different folks and all that, but I’ll add my personal opinion. It’s likely to be quite a bit different from everyone else’s here (can’t say I read all of 'em).
It’s completely one thing for Partner A to dictate Partner B’s social relationships. This (in all realistic-ness) is just plain silly. You cannot go around saying, “no, do not speak to Cindy Lee because to be honest - I don’t like her.” Before you say so, I know it’s not what you did. Be patient. I have a point.
But it’s quite another thing for Partner A to be insulted by Cindy Lee - and then to have Partner B to chat with her as if nothing else had happened (at least IMO - and I speak as a guy).
I would expect my girl to expect me to at least be far more distant with this woman, particularly if she had insulted (our) kids. You can argue “oh the truth hurts” and all that schlock, but the “truth” can be expressed in a classy way - or it can be expressed in the complete absence of (and I don’t think it was a passing comment to make).
Now you can look at that as “oh you’re being so stringent - how dare you dictate who my friends or conversational partners are!” but I would say that in this case, it’s more about loyalty. I’m not saying your hub should go slap this woman round like a bitch-hoe; nor should he even get involved in the argument (it’s not really his anyway) if he really doesn’t want to. That’s gotta be his choice. But to turn a blind eye to it completely, to me anyway… smacks of disloyalty. At the end of the day he’s with you, not her. Yes he doesn’t have to give her death stares as she walks across the street - but neither does he have to walk around showing his pearly whites (if they really are that color - hell FAIK they could be green as fungus) everytime she shows up.
Another thing is your personality. Now to be practical, it could just be that you are argumentative (I said could, keep reading). You could be getting into fights left, right and centre and this can have a deleterious effect on a relationship. If this is the case, it’s understandable why he wouldn’t want to get involved in any way shape or form with this argument.
But if this is the case, it’s his job to TELL YOU - you can go on sorting it out from there.
However if (by most accounts that he has with you) he knows you to be a person of sound mind and body, and you claim this woman has offended you in this way, you probably should let him know about exactly why it is this is bothering you so much - and, IMPO, he should back you up with it.
Remember everything is about balance - if we all stopped communicating with people who pissed off our SO’s, nobody in da big wide world would speak to each other. It’s all about comprimise (God, I sound like one of those weirdo Agony Aunt’s don’t I?).
But once again IMHO he sure as hell shouldn’t be pissed at you for this whole scenario. I mean you were only asking.
I will take exception to one comment though:
We’re not talking about cutting off his oxygen supply with the rest of humanity here. This is a woman who insulted his wife - and he should show some signs of sticking up for her (his wife, not the ogre).