One of the most interesting things that even exist on the Internet, and yet they do. Tons of them. Though of course they usually tend to be mostly porn with some SJW ramblings scattered in, but they're ultimately one of those things that I realize is in fact really bizarre but that I'm not phased at all by due to how desensitized I am to them, similar to the existence of Christian emoviolence.
My personal favorite was running across a Tumblr that was mostly extreme BDSM stuff yet had an entry with the gifs from
here in it.