That's sufficiently the opposite of the norms he's used to that he can't tell if his instinctive thought of nope is coming from his preferences or his professionalism. Also, he's currently talking to her brother. "Er. Noted."

"...I'd tell her you don't like sex but I think if your world is all nondynamics it can't be that half the population doesn't like sex."

He really does not feel like going into how he would probably like sex if he had ever had any with his very polite host who continues to bizzarely resemble his labmate. He would rather grade a hundred midterms, actually. "I think most people in my world like sex, yes."

"...I don't know how your world handles things but I think you should probably get the whole thing straightened out with me, a person who is totally uninterested in sex, before you accidentally offend the wrong person. Or worse flirt with them."

"Yeah, okay, fair. How do I avoid doing either of those?"

"Uh, I'm not sure how finding partners... works... in your world? Here you can see whores"-- the term implies "submissive"-- "or take another nondynamic or a dominant as a lover. It's a bit strange to have a dominant lover who's not your patron but not that uncommon."

"My world also has sex workers, and people date their friends or their co-workers or people they meet in bars."

"...so that much is the same. Uh, if you want to flirt with a dom you want to look like this"-- he rearranges himself so that he looks smaller and weaker and more vulnerable, and his eyes gaze up at Bruce with adoration-- "if you try something else they won't understand what you're doing. And you want to be all"-- his voice changes-- "'I'm scared, ma'am. You can do whatever you want to me, ma'am. Oh, please don't hurt me. I'll do whatever you want, ma'am. I'm all yours.' Or there's bratting but that's more complicated-- deliberately disobeying orders so that they'll punish you-- some doms are really into that." 

Oh no, being gazed at with adoration is giving him some sort of emotion even though it is blatantly fake gazing for example purposes and neither of them is even into men. Stop it, brain. No emotions allowed. "Okay, I will avoid doing that."

"If someone tries that on you you might want to tell them you aren't into sex or you might want to just go along with it. Going along with it's easier."

"Why would going along with it be easier? I thought sleeping with a submissive would be bad for their reputation and I wasn't supposed to do it?"

"Sorry, don't sleep with submissives. But if a dom says"-- tall, strong, forceful body language; calm and firm voice; he's less good at this than the other one-- "'you're such a pretty thing. You're mine, you little slut. I'm going to pin you up against the wall and take you and there's nothing you can do about it', it's often easier just to not object." 

"I see. That's good to know." Is this how women feel all the time? Not that it's going to matter, he reassures himself, because nobody is going to want him.

"Honorable doms won't, but some people conclude that we all don't like normal sex so it doesn't matter whether we want it in this particular case or not."

Nod. "Anything other than those two ways of behaving that's considered flirting? I realize that's a really hard question, since pretty much anything can be flirting in the right context."

"If you're with another nondynamic and they keep making excuses to be alone with you and telling you how great your work is and how insightful you are, they either want to have sex with you or cowrite a monograph."

"Okay, that's actually adorable." It's kind of awesome how this world has an entire gender of nerds, even if it sucks in some other ways.

"And they stop when you say 'no' and you don't get bruises afterward, so it's a much nicer experience really."

"I can imagine." And presumably so can Maturin, since he isn't interested and has therefore only had sex with people who don't stop when you say no. Fuck.

"Whores are probably simplest if you don't mind submissives. Whores like nondynamics, we can't get the girls in a family way and we don't like hurting them."

"I guess that follows." And he would really rather put off the question indefinitely; he coped with being a virgin his whole life up until now and he can keep coping. "Is seeing whores legal here? It's banned in most places back home."

"Yeah, of course. If whores exist it helps dominants remain faithful to their submissives."

"Because it doesn't count as cheating if you pay for it?" 

"Well, I mean, it's not good to see a whore if you're married, but dominants have needs and they can't always get it from their own submissives."

"That's definitely not how my world does it but I can see how people would get there." He doesn't approve, but he can see it.