Very improper

Whatever it is that Henry is doing that Catherine likes but does not wholly understand, it enables him to slide into quite questionable territory quite easily. As soon as Mrs. Allen joins them and talks of muslin, Henry uses this to discuss Catherine's gown, to gravely examine it (and we do have to wonder what parts of her he looks at while doing so), to suggest that it will fray, and to talk about cutting it to pieces. he does all this under the guise of furthering a discussion of the practicalities of muslin introduced by Mrs. Allen.

Pretty good work that.

And, flogging my favourite subject again, anyone who thinks there is no awareness of sexuality in Austen ...

You doubt me? Read a couple of paragraphs and tell me this isn't sexual:

"And pray sir, what do you think of Miss Morland's gown?"
"It is very pretty, madam" said he, gravely examining it; "but I do not think it will wash well; I am afraid it will fray."
"How can you," said Catherine, laughing, "be so —' she had almost said, strange.

Read something like that and you have to wonder if the people who find Austen sexually repressed are very sexually aware themselves.

Her person and disposition at 15

Things change. She stops being such a tomboy, she begins to care about balls and dancing, she puts more effort into her appearance. She begins to appreciate compliments and, Austen is at some pains to make us understand, these compliments really matter to her because she is not a great beauty but only a girl capable of looking pretty.

Something else changes and I stop here to underline this detail because it can slip right by us:

At fifteen appearances were mending; she began to curl her hair and long for balls; her complexion improved, her features were softened by by plumpness and colour, her eyes gained more animation, and her figure more consequence.

Emphasis added as they say. Yes, her breasts and hips grew. She became a sexual being, no longer a child. Austen speaks of these things in a way that seems circumspect to us but is actually direct and to the point. Sex matters and never does Austen dodge its importance.

Did they or didn't they?

Okay, I'm really sticking my neck out here but I think something of a sexual nature, although not actual sex takes place between Willoughby and Marianne.

One of the reasons I like the Bitch in a Bonnet (I assume Robert Rodi means himself and not Jane Austen by that) is that he compensates for some of the misleading readings of Austen by "going too far".Fans of Sense and Sensibility will remember that Marianne and Willoughby disappear together at one point and we later find out that he took her to see the estate he may one day inherit. And we are shocked to further learn that they went inside and no one was there so they were inside and unchaperoned. So what does the Bitch in the Bonnet think happened?

Elinor is shocked; she must suspect, as we do, that Marianne’s criticism of the house’s unfashionable furniture is partly due to the lack of comfort to be found there when you’re flat on your back with your ankles in the air.

At which point a lot of Austen fans recoil and say "No!" But should we?

There are two huge misconceptions that need to be cleared away here. The first is that Austen was sexually repressed and/or sexually unaware. That is nonsense as anybody willing to read the books with their eyes open will see. The second misconception is that extra-marital and premarital sex were unusual things at the time. They were not.

But here is the thing, you don't have to read it either way. The novel can be read consistently and plausibly either way. Austen not only doesn't connect the dots, she sets it up so you don't have to either. If all you want to see is that they did a shocking thing in going inside alone, that's all you have to see.

Or you can read more into it. I do, although I read less than Bitch in a Bonnet does. I suspect she got pinned to the wall, kissed, felt up and maybe he got some pleasure from gently thrusting himself against her a bit he doesn't think she noticed but she did. That matches my reading of Willoughby and of Marianne.

What I think can't be done, however, is to settle on an authoritative reading for everyone that excludes the possibility of sex. As is sometimes said of the Book of Ruth, whether you think actual sex happened or not the sexual tension implied by its very real possibility is an essential part of the meaning of the story.