What follows is explicitly sexual in nature      For anyone, like me, who loves putting things in their butt, but who has always wondered about the mechanics of what’s up in there, here’s a primer for you.        Biological male reproductive system      On the outside of the body when you spread the butt cheeks you see what is called many things: puckered starfish, balloon knot, leather cheerio, my favorite snack, rusty sheriff’s badge, ojete, et al. What you are seeing is officially called the anus, defined by websters.com as “the opening at the lower end of the alimentary canal, through which the solid refuse of digestion is excreted." Websters neglects to mention that the anus is also the opening of an organ as experienced by countless people the world over.    Biological female reproductive system    As you move inside the anus the first thing you encounter is the rectum, essentially what I see as my fleshy fun tube. Now, I’m not one of those size queens who prides myself in how much dick or whatever I can…