Over the years his knots had gotten stronger.
She remembered, fondly, the first time he had bound her. The man was clearly no boy scout, and could do little more than recreate shoelace "bunny ears" on her wrists. She didn't try to escape, but by the end of the fucking the two of them had wound up embraced in a virtual spider web of loose ropes that comically wrapped their sweaty bodies.
But he learned, and he learned fast. As their collection of toys in the little drawer next to the bed grew, so too did his skill. Within a few months he could have her helplessly hogtied in just a few short minutes. Or at least she believed he could. The bastard always took his sweet time, following the same process.
First, he'd instruct her to strip and kneel. She reveled in the feeling of submitting to him. Of finding herself below him, naked, while he moved about fully clothed. Eyes lowered, nipples hardening from the combination of the cold air and anticipation. She knew what this time was for.
Next he'd affix the gag. Every time it came on she thought back to when she bought it, to how he had made her feel. She was mortified, despite herself. "I've been bad and I need a ball gag." Were the precise words he had told her to tell the clerk. She rushed back to the car afterward, bag in hand, cheeks red with embarrassment and excitement to show him what a good girl she had been. He took the gag out, examined it, and decided he didn't much like the color, and sent her back in to apologize and exchange it.
With the gag in place and eyes lowered, it was easy for her mind to transition. She was no longer the independent woman who managed six employees (including Darren, that idiot). She was becoming His. Lights dim, Sir slowly deciding which toys he might choose that night, and how he felt like taking his pleasure. Her mind slowed down, and she focused on the feelings in her body. She relaxed into the feeling of being owned, of being cared for.
He chose to have her arms tied behind her back this night. And she was able to predict that he wouldn't be attaching her to the bed. The bed they had sought out and chosen when they moved in together. It took several trips to find one that looked strong enough for what He had in mind, to say nothing of a specific type of headboard and footboard that would lend themselves to the anchoring jobs they'd need to serve.