Possible reasons my neighbor screams so loud during sex

There's gotta be a reason because no one is that loud just because they enjoy it.
  1. She's filming a porn.
  2. She's actually being stabbed, like with a knife, not a penis.
  3. She has that "somebody scream" club music on a loop in the background and likes to follow orders.
  4. She can only speak in morose code using short and long screams and is actually directing her partner.
  5. She thinks that whoever screams the loudest wins.
  6. She believes in faking it until you make it.