Nudist Bondage Sacrifice
This comes from Kinky Delight, but if you follow back the links, it looks as if it may have originally been found in the classic naturist journal Helios. So perhaps we are looking at a Burning-Man style nudist-camp ritual? Hard to say. Looks like a hell of a party in any case!
She’s smiling. Whatever is about to happen, she is looking forward to it!
Maybe she’s giggling because of the spear at the far left. The man might have reverted to an atavistic state, but he has thoughtfully decorated the top of his spear with a French tickler.