There's... a lot to read here. She wasn't kidding about having so many thoughts.
He agrees with her about the um, fluids situation. The enema thing is hot in theory, mostly, but the amount of description it got (and also Himari going around all full of liquid and needing to pee) was not exactly a part he enjoyed reading about. It does make sense, kinda, that she was doing it to apply things via the inventive ROSEFUR method (which is still neat) (also the parallels where both of them are smart is pretty clear) -- but also if you're going to make areas sensitive, he's not sure why you'd do more than like, the part of the butt where the penis goes. If that makes sense.
And, vis a vis fluids, he's also not really a fan of the milk thing either? (There's far too much porn of it and he doesn't like it and wants instead a different thing.) He sees Rosy's point about the whole feedback loop thing, but, maybe use sweat glands or something? Though sweat is not sexy. But it's better than breast milk (ugh).
Realistic or not, the kink menu (though very, very extensive) did seem pretty hot. The ability to just give people kinks so they could be what you wanted or enjoy the things you wanted to them... that's hot. A little clinical, but hot. And Rosy also finds it hot! In real life (which possibly he's going to have access to, which is neat and scary and exciting and scary) he would also want a back-and-forth, yeah, he's not about to do things to her without talking to her first, that way lies bad things, but even so the idea of her head being that customizable (which it might be? He should ask?) is hot.
He liked the way she was begging and struggled. Begging for things he's experienced in porn before (and likes a lot) but the whole concept of denial was new to him. (Still is, though he mayyyy end up searching it out later. Maybe.) And the touch thing is a part of that. The idea of ordering Rosy to be horny and not be allowed to touch herself... yep, he's enjoying that. He shifts in his seat. Rosy says her tolerance for that is less than Himari's but that's like saying a frying pan is colder than a forest fire. Or a volcano. Or the sun. Still, he should probably actually give her the thing in the end, the whole point is for her to keep wanting it.
And then in terms of 'bullying'... wait.
John realizes that he's been sitting staring at his phone reading through Rosy's words for a couple of minutes. And hasn't said anything. "I um," he says. "Should I be, um, talking about these things with you? Instead of just reading them on my own?"