Oh, I always read the warnings, and it wasn’t my intention to complain about anything*. I just couldn’t think of anything to say about the latter part of your story, because it really succeeded in shocking me. :)
For one thing, I wasn’t expecting them both to enjoy torture. Secondly, the shift from hot to repulsive was sudden and surprising. And final (at least to me it was). There’s also the fact that the victims’ agony felt all too realistic. *shudders* Actually, I don’t think you used any of the usual non-con/torture clichés for which I would’ve been prepared. For what it’s worth, I appreciate the creativity and skilful writing, even though the story as such isn’t my cuppa.
*Although, and this is just my opinion, I would add a warning for dark fic and take out the bloodplay warning.