It was a Hentai. The guy had some kind of thing that linked him to the pussys of other girls. It was like a circle but inside was the pussy. The girls felt evething he did. I think he molestet some girl all the time and he fucked here in the end for real. I think it was like in Happy Peach if someone wants examples.
If I wanted to, I could link you several ones straight from syosetsu, but to my knowledge, those particular ones have never had any translated chapters, so i'm pretty sure they're not what you're looking for. But if it was actually H manga or anime, then I can't really help you, as I might only have seen one of each and no memory of it. My suggestion would be to go to Happy Peach's syosetsu page, find the specific genre / keyword for the 'holes' and search with that .
i love how so many people came together to help a man find his desired porn, giving such serious answer.
I think I read something like that a long time ago. Did he get bullied by some girls and then some mysterious girl appeared and give him gadgets (?). One of them is the wormhole ya mentioned, another is some mark that makes one girl experience the sensation of the other girl while he fucked said girl. That's all I remember for now.
I would never watch something as low as porn. And you should never use porn when speaking about hentai. Mind your words.
I remember this one. The one where everyone gets pregnant and they treat it as a gift from god due to the declining birth rate of japan.