Aliens.

"...I guess when they said we would do exposure from you to me later, I don't think they technically specified that it would be at least one expected-incubation-period later, even though for all practical purposes doing two exposures within one incubation period is effectively doing them at the same time.

...the important thing, for the medium term, isn't whether it's fully safe for me to be exposed to you: the important thing is whether sustainable sanitation practices are sufficient to protect me from you. If local microbiota are so dangerous that even wearing this respirator and showering when I go back inside is enough exposure to kill me, it makes sense to go ahead and find that out now before the loneliness does any more psychological damage to me." He'd never be alone again, after that. "If I can interact with the world by...the kinds of measures I'd take if I were a mildly-to-moderately immunodeficient person interacting with fellow Rekkans, if I can go out in your towns as long as I'm wearing this respirator, if I can hug people as long as I shower at the end of the day, it's not urgent to find out whether that's still overkill. It's especially not urgent enough to risk the only fluent Tashayan speaker on the planet, when we haven't had time to fully train up new translators yet."

(It's dawning on him, in horror, that thus far he's focused on preserving knowledge of Tashayan such that they can understand alien writing. Speaking should be pretty intuitive from there--the Tashayan alphabet is pretty much phonetic--but he's done essentially nothing with signing, and if he departs at this point they're going to lose an entire modality. He places "make a signing dictionary of those top five hundred words, and record demonstrations of some basic grammar" at the top of his mental to-do list, just above translating the PPE articles.)

"...are any of the other quarantine suites unoccupied? Can you live nearby for a while, and I come and spend a few circuits each day with you? Breathing on you," he gestures at the respirator valve, "and touching your things, and still having a home of my own to go back to at the end of the day?"

"They are available, yes. But walking over with what you might have is a risk I don't want to impose on others; I'm happy to be outside, here, and then fly off to be tested after some time to let anything you could have given me incubate. I think you're underestimating how nice a tent and sleeping bag could be, for me; I'm happy to be here for just the few days it'd take to see whether anything harmful happens when exposed to you."

He feels like he's floundering a bit.

"...yeah, that's true, it makes sense to keep things inside the birdcage right now," he says. "I can spend a while each day hanging out in your tent, then, practising a level of exposure-from-my-perspective that I could later sustain while..." he looks distant, remembering the person who came to collect the sample "...seeing the world, if exposure-from-your-perspective does turn out not to be an issue."

"...maybe we should take some time off from each other, then? I have a phone, and I'm in the mood for some reading on it by myself now." She starts sitting on the ground, tapping on her phone. "And you can keep transmitting your culture into ours."

That feels like something that might have alien subtext (offended that he doesn't want her in his house?), but given the more overt text it doesn't seem like a good idea to ask right now.

"Okay."

He gives the bird one more pat, then heads back inside, doffs his gear, showers, and settles in to make a basic signing dictionary.