LOTR RPS is mostly out for me because I don't want to think of the hobbits having sex! (Or the actors who play them, LOL.) That leaves out Monaboyd and Monalilly for me or Dom getting mixed into the Foxshy equation in a sexual way. Especially if Dom ends up on top. Just... no. NO!!
But then I went and wrote a Foxshy fic with Evie (Open) and was prepared for boos and catcalls. But, I'm overwhelmed at the positive reaction to the fic so far! It was inspired by foxxcub's fic Pirates & Eyeliner, which had at least one person asking for an RPS threesome afterward. She said she didn't want to write something like that but I had an idea and I went with it. And then when I showed it to her, her response was "OH NO YOU DIDN'T!" Seems I hit a squick of hers by letting Evie off the hook, in a sense, by imagining she was Kate getting it on with Jack and Sawyer. ;-D Blending RPS and regular fic just was too much. So I thought about it and decided she was right and it was more subtle to just have Evie call Josh "Sawyer" once.
So far I've only had one (anonymous) response to please just leave Evie out of future Foxshy fics. Fair enough! We all have our areas that squick us out. For me, it's mentioning anyone's wife by name or having her appear as a character in the fic. It's one thing to play with the actors but quite another to involve private citizens. That's maybe an odd take on it, but I can't help it! It just ruins all the fantasy for me and I have to stop reading!
So what are your RPS squicks or does the whole concept disgust and horrify you?