Does anyone remember seeing this story lying around somewhere?

I think it was around 2-3 years ago that I remember reading a futanari story that revolved around magic and transformation at a high school.

A boy dragged his friend into the girls' locker room to help him take some nudie pictures. While they were hiding in the lockers, they looked through to see that the cheer leading squad was in reality a witches coven. In the midst of doing witch stuff, the kid is stupid enough to take a picture and get noticed by them. As a result, both him and the friend are dragged out and girls magically replace their clothes with lingerie, give them more feminine hair doos, and then make their genitalia really tiny.

After that, the coven endow themselves with large penises and gang rape the permanently changed unfortunates.

I can't remember where I first read it. I suspect it was either Nifty, Literotica, Fictionmania, or asstr but I honestly can't remember if I had discovered those sites back then. I'm damn sure the story was notable enough for some futa fans to have held on to it.

Anyone know?