The mirrored familiarity is what makes her smile, crooked — all those times she's briskly offered context for something, uncertain of just how much translates or doesn't — and frankly, given some of the conversations she's had over the years ... she suspects this, particularly, is less of a Thedosian versus rifter potential gap so much as it is,

“Don't worry, I've written too much poetry about my cunt to be unfamiliar with the term,”

a question of, say, lifestyle.

When she spreads her thighs wider, either side of him, she doesn't immediately let go; it's important to hold a man's attention when imparting essential knowledge. “I like it firm,” she says, “and I like to be held down.” Grip is an issue that they're both aware of; the fact that she continues, “Don't worry about bruising me. Use your elbows.” —perhaps suggests that, maybe, she might have thought about this before a bit.

Hypothetically. A little.

And then, aware that she gives a particular impression— that she has run into it before—

“I don't— need,” want, “to be in charge. But I know what I like and I don't mind saying. I want to know what you like.”

It's invitation as much as instruction; she's invested in his pleasure.