Mistletoe and Masks (Yule Tied)

Hyper Luke McKellen is Lock, a superhero with a dominant streak who yearns for his lovely partner, Ultra, AKA Nikki Moss. Trouble is, he thinks Nikki's too vanilla -- and too powerful - to ever submit.

Nikki is obsessed with Luke, but she's always believed he'd be contemptuous of her submissive fantasies. She's astonished and delighted when she encounters him at a BDSM club Christmas party - until he demands proof she's more than a sexual tourist with a taste for Fifty Shades.

Luke's got his doubts this strong woman really wants to submit. And even if she does, how do you dominate an invulnerable woman who can bend steel with her bare hands?

Trouble is, Nikki's skin may be invulnerable, but her heart is not.