Written by *butterflydreaming, Hall Pass is a Rapunzel/Eugene/Elsa fic response to Elsa's Dungeon, the comic that scarred me:
Trust, negotiations, and fluff are incorporated into it to make it less jarring, but this is only for the Mature crowd (Bonbon88, I'm looking at you). I would still read with caution, and there is a caution warning you have to get past before you do. Do not read it if you know you aren't supposed to be doing so or happen to be unfamiliar with BDSM like I am.
*Parfait (+18) by butterflydreaming
She's the popular authoress of *Elsa of Corona who decided to take on a polyamorous romance bet