I'm going to start this real slow and lay out the facts: Knotting is a popular trend in fan fiction. It involves men having sex with men like wolves. And it often leads to male pregnancy, which leads to male delivery. And the people giving birth to feces-covered babies are often members of One Direction.
I first learned about Knotting (which is part of the Alpha/Beta/Omega universe — more on that in a bit) when I read about the failure of Dash Con, a tumblr-related fan convention that just went horribly wrong. Among the myriad of issues at the con, one was that minors were being allowed into a panel title "Can You Knot?" which was supposed to be 18+ only. Not familiar with the term, I googled it, expecting to see something about people asphyxiating each other, but what I found was something much more interesting: Fictional characters from music, movies and TV fucking smelling each other's glands and biting each other's essays. And, of course, having anal intercourse that results in the creation of more heirs ready to do the same. And because I know about it, now you have to know about it too.