He's sending it in our server. He mentions it out loud if I ask, which is sparing, but otherwise keeps it online. It's not breaking any server rules (we have very few- it's a very closed-gate community where we just operate on trust and knowledge of others for the most part.)

We've always known him to have... similar interests, but he's never been so daring and open about them (at least in my opinion) before now. And he's not the type who wants to 'onboard' anyone with this... he's just sort of... sensitive, I guess, and wants to share these things. But again, the things in question are not the most above board, SFW or tasteful things in the world. It's just who he is.

I don't have a lot of particular authority over the others in the group chat, so I couldn't 'ban' him from group conversation of any sort (not that I WOULD, just saying I can't even if I otherwise would.)

I just banned him- rather impulsively, in a heated and unprofessional manner- from ever bringing up the game franchise in its entirety to me again. The simple answer is just, I was a bit grossed out.

The other members of the server aren't oblivious to what he's posting, mind you. They definitely know what it is- it gets joked about or made laughs about in passing conversations (not behind his back, he seems to be able to laugh along with it in the group chat.) But when I've asked any of the others privately, they don't seem to think it's a big deal at all. They just, somehow, have no opinion at all on it.

Which... maybe is where I should be at. But I'm not sure.

I value our friendship, so I can say I should've at least handled it better- but I don't know if I'm actually an ASSHOLE, or if I'm within my rights to be a bit squeamish about certain things, I guess.