First things first, it's not what you think, so relax.
Secondly, don't actually relax because you will be thoroughly sickened by what you're about to witness, so maybe choose your moment to watch this when you won't be judged for screaming 'EUGHHH' out loud.
Thirdly, put down the fork/spoon/sandwich. Food is not a suitable accessory to this viewing. Please don't try this at home. It's just not advisable.
