I'm baffled by Edmund's reaction - or lack of it - to Mary's smutty joke.

At the dinner party in ch.6 Mary puts her foot in it a couple of times. First, when she is speaking of the inconvenience of the Admiral's improvements at the cottage in Twickenham, she refers to him ironically as "not the first favourite in the world" and "my honoured uncle". Here's Edmund's reaction:

Edmund was sorry to hear Miss Crawford, whom he was much disposed to admire, speak so freely of her uncle. It did not suit his sense of propriety, and he was silenced...."

A little later Mary goofs again:

“Do you know anything of my cousin’s captain?” said Edmund; “Captain Marshall? You have a large acquaintance in the navy, I conclude?”
“Among admirals, large enough; but,” with an air of grandeur, “we know very little of the inferior ranks. Post–captains may be very good sort of men, but they do not belong to us. Of various admirals I could tell you a great deal: of them and their flags, and the gradation of their pay, and their bickerings and jealousies. But, in general, I can assure you that they are all passed over, and all very ill used. Certainly, my home at my uncle’s brought me acquainted with a circle of admirals. Of Rears and Vices I saw enough. Now do not be suspecting me of a pun, I entreat.”
Edmund again felt grave, and only replied, “It is a noble profession.”
“Yes, the profession is well enough under two circumstances: if it make the fortune, and there be discretion in spending it; but, in short, it is not a favourite profession of mine. It has never worn an amiable form to me.”

It is clear that Mary did mean to make a smutty joke - by disclaiming it as a pun she effectively draws attention to it.
Note that Edmund feeling grave occurs immediately after the pun and before Mary's second statement (in bold) which is indirectly critical of her uncle.

Then in ch 7 we have Edmund and Fanny criticising Mary:

"But was there nothing in her conversation that struck you, Fanny, as not quite right?”
“Oh yes! she ought not to have spoken of her uncle as she did. I was quite astonished. An uncle with whom she has been living so many years, and who, whatever his faults may be, is so very fond of her brother, treating him, they say, quite like a son. I could not have believed it!”
“I thought you would be struck. It was very wrong; very indecorous.”
“And very ungrateful, I think.”
“Ungrateful is a strong word. I do not know that her uncle has any claim to her gratitude; ..(snip) ........ I do not censure her opinions; but there certainly is impropriety in making them public.”

"..... And what right had she to suppose that you would not write long letters when you were absent?”
“The right of a lively mind, Fanny, seizing whatever may contribute to its own amusement or that of others; perfectly allowable, when untinctured by ill–humour or roughness; and there is not a shadow of either in the countenance or manner of Miss Crawford: nothing sharp, or loud, or coarse. She is perfectly feminine, except in the instances we have been speaking of. There she cannot be justified. I am glad you saw it all as I did.”

The whole of Fanny and Edmund's criticism is directed at the impropriety of Mary expressing even oblique criticism of the Admiral, presumably because she ought to respect his role as her guardian/parent no matter how unpleasant his behaviour is.

My instinctive reaction is that the pun is a much greater impropriety than disrespecting the Admiral. I'm not especially sensitive to bad language or dirty jokes, but even today I think that if a young woman uttered a line like that pun at a dinner party attended by respectable people of mature years it would be an absolute conversation stopper. Priorities were presumably different in 1813.

What I really find baffling is Edmund's reaction. I could understand that Edmund might not feel equal to discussing Mary's coarse pun with Fanny, but he actually states that there is nothing coarse about her! Oh really???

I don't get it. Are his hormones afflicting him with selective memory, or what?

Thoughts anyone?