Stuttering HIPS???

I checked out the tip here about K.A. Mitchell and read a few excerpts on Amazon (question aside, does anyone know whether I can buy e-book versions not Kindle of her books anywhere?), and that's where I came across "his hips stuttered" to describe that he came.

That was a new one for me, not just that while I have seen many men ejaculate many times and up to the most hefty O's wrested from them, I really never came across anything I would describe as "stuttering hips." Yeah, stuttering men I met a couple, but they did that while trying to talk. Spurting ejaculate, that I also met with quite a bit. Thrusting hips too. But heck, no stuttering hips.

And what bowls me over is that it's not the first time I heard about "stuttering hips" in fiction, I've seen it one or two times in fanfiction, but well, that's not been run past an editor I told myself. But now I read what clearly must have been run past at least an editor and someone reading the copy for errors and typos too. And still that is in.

In short, where does this come from and who created that atrocity?

Irregular thrusting that happens during ejaculation could be called stuttering since it throws off the "normal" rhythm.

Synesthesia.

Stuttering hips?! That is wayyyyy too purple for me. Give me a break! Wow.

Best guess? Someone misheard and assumed it was a phrase: "shudder" ---> "stutter."

Once it was put on the internet, it got around and then the editor either assumed it was part of the author's style or was under a similar impression as the author.

(Seeing/reading this reminds me of people who write "an other thing," honestly.)