It was a sudden and out of place as if the next chapter was all 3 of them going to a boys school for a gangbang.
I definitely wouldn't say that, since introducing hetero and a hetero gangbang at that would have pissed off even more people, and made people potentially hate the author. As it is right now people just don't like the direction this took, but these forums would have gotten way more intense if it went the route you're saying.
All the angst here about the intrusion of the classmate and the logistics of her anal self-pleasuring seem to ignore just how literally sketchy and spontaneous (I was going to say “tossed-off,” but decided against it) the story has been from the beginning—the dashed-off art and the text-only transitions indicate that this isn’t supposed to be a completely plausible narrative set in fully realized storyworld. The story looks like it’s just a fast-food delivery container for scenes that the mangaka wants to draw.
I suspect that this story serves as the mangaka’s relief valve for all the serious NSFW impulses bottled up from Virgin’s Empire. Sometimes an author’s work isn’t primarily for you, it’s for them.
Yeah I think that's the thing, this seems like a quick and dirty comic where author is making something smutty that they want to draw. As for the pacing I think this is supposed to (probably at least) be a short more porn focused comic than anything professional or serious.
All of this said though I personally don't like the addition of the 3rd character, and I wish if anything her phrasing would have been more "since you the two of you came here to have sex, is it okay if I watch?", something less forceful where she can be invited into the dynamic. I also would have liked a somewhat more long term series focusing on the original two characters, with more natural pacing. So I don't even disagree with the critiques for the most part. I just figure a series like that probably wasn't the creator's intent to begin with, and I guess at this point my main hope is that the new character doesn't commit worse and worse acts. We'll see how it goes though.