Started working at my then local game store a handful of years ago. I got to know this guy and we quickly became friends outside of work. We would game, skype and all that jazz. He's openly bi and will often go on a tangent about his sexual experiences (with both genders mind you) share stories about his different kinks and weird gone-wrong-stories too.

At some point he linked me a reddit post he had commented, so naturally I friended it, I've done that with a lot of my friends, I didn't give it another thought. He startet out commenting a lot in various gaming subreddits, but over the time it got more and more sexual, and he started posting tumblr pics of himself in a lot of fetish NSFW subreddits and the pics are in no way SFW. I don't judge the guy, I mean that's what he's into and that's great, but I'm 100% sure he knows that I know his reddit username.

I haven't really spoken to the guy in a couple of years at this point and the NSFW posts just keep on coming. We've played together on occasion (we've both moved to opposite ends of the country), and I can't help but feel extremely weird about the fact that we both know that I've seen his stuff on reddit but noone's said anything. I have no idea if he's friended me on reddit, but there's a very big chance he'll read this and recognize my username.

You'll definitely know who you are and we don't need to bring this up at all. It's cool, as long as you're happy, that's all that matters. I could've just not looked.