Looking for a doujin where a students fuck his class members

>>15060702
yo, i saw that one too. spoilers but the scene where it happens involves rope, and there's a symbol at the place of his body where the dick used to be, and there's a scene where it sticks to a chair and spins, inside of a girl

I vividly remember so many scenes of it, but i don't want to spoil the entire thing here.

>>15060707
Oh, never mind, wrong one. I've seen the portal one too, though. He eats her out through it first before fucking her through it. It's the size of his hand.

I was thinking of a disembodied dick doujin.

>>15060702
You'll have to be more specific about the portal, it was a mirror? Smartphone? Onahole?
There's many authors that have used that plot.
Could be this one:

[Yokoyama Naoki] Cockatrice (Siren -Kyousei Saimin Keitai-) [English] [naxusnl] [Digital]

...but you should look in the female:wormhole tag, there's 105 raw and 39 in english.

I recommend this one too (anal):

[RAYMON] Anal Kaihatsu Appli | Anal Dev App Ch. 1 (Anal Choukyou Appli) [English] [CrossRook] [Digital]

>>15060708
It's that one!

>>15061003
Right? The guy pulls her panties to the side before eating her out, and he does it in the classroom. You see a noticeable bulge of her puffy vulva through the portal. It's like a circular portal.

It shows what he wants to see most, right? Just going off of memory. I don't have the source, though, sorry.

>>15061007
Holy shit, i'm also going on memory from years ago and i'm also remembering it vivedly.
Replying is enough, thanks!

>>15061011
No problem!!!!! Good luck