An Adorable Slave (Part Four)

Just as she is about to become the complete dominant in the strange relationship between Preston and Beth, Maura discovers a new facet of the couple and realizes she should have seen it long before. It doesn't stop her at all-she uses her knew bit of knowledge to subjugate the couple to her will. This is an 11, 000 word novella intended for adult audiences. Part four of four. Content warning: features strong erotic relationships, consensual slavery, spanking fetish, graphic sex, group sex, lesbian sex, BDSM sexuality, erotic situations not all members of the public will enjoy, and other depictions of adult sexuality.
Explicit language and adult only content. Excerpt:"You ready to have sex with her?" she asked Preston. He nodded. "Uh-huh."She stroked him a couple more times and asked, "Are you sure you wouldn't rather have sex with me instead?"His eyelids had dropped down a bit giving him a spaced-out look, but that question made them snap fully open. "What? I mean, sure, that would be great right now, if you want."A laugh escaped her lips.
He wanted to please her and he also wanted to submit to her at the same time, also while attempting to remember that he was the one who was supposed to be in charge. But Maura knew that he was a switch and she was the true domme in this triad. Maura put a hand to his chest and shook her head. She fell to her knees in front of him. Beth had slowly twisted around so that she could see the pair, even with her downcast eyes.
Even on her knees she knew she was in charge of him-she wondered if Preston realized that.