He is only pretending to be exasperated. He never gets this nice a reception.
Professor Reed looks torn between laughter and rolling her eyes. "In light of the... unusual circumstances... I will excuse food in the classroom for now. Just this once," she adds with a look at the previously mentioned Mr. Parker. "But Cam, if it's not too much trouble- I would appreciate napkins, please."
"...also, I'm Emma. I don't think I said. It's nice to meet you." She nods at Jenny, who is halfway through her ice cream cone and entirely unable to talk. "And Ms. Chocolate over there is my roommate Jenny." Jenny beams and waves and does not in any other way cease her consumption of chocolate.
"Napkins," says Cam, producing a stack of them and placing them on the nearest surface. "Nice to meet you. If I wind up sticking around for any prolonged period of time I will want to keep track of you so you can send me back after."
"If it's easier, Cam," Professor Reed says, looking slightly uncomfortable. She is clearly not used to a lack of a last name. "I'm sure the university would be happy to host you somewhere in exchange for- well. Whoever won, the bureaucrats wanting supplies made or the teachers wanting to study your form of magic." She looks curiously at the pile of napkins. "You really just- create things? Anything?"
"I don't have email or a phone here - I can make stuff, but that doesn't mean it'll connect to an existing network that charges for access," Cam points out to Emma. And to the professor: "Do you want my last name? I have one of those too but I haven't used it in a hundred fifty years so it'd be sort of strange. I could use a place to be, although if you didn't offer me one I'd just find someplace nobody was using and make myself a house. I can create arbitrary non-magical matter given a reasonable amount of information about what I'm aiming to make."
"If you prefer Cam I will of course use Cam," Professor Reed assures him. "It's just... non-intuitive for me, to simply presume." She thinks for a second. "Why don't I just go ahead and call Dean Scott? I assume it would be easiest for you to have this all worked out." Under her breath, she adds, "if I can even explain this."
"Sure, go ahead," Cam tells her. And to Jenny: "A cuuuuute boy who can hear you, who just casually mentioned being over a hundred and fifty years old, and who doesn't appreciate being used as ammunition."
Jenny just shrugs. Emma is used to her; Cam is not. "She knows I'm kidding, you already said you need her phone number for actual reasons? I'm sorry if it upset you, though. Totally not the goal." She looks him up and down. "A hundred and fifty? Really? I thought you were exaggerating. Is that a demon thing?"
"Hundred seventy-two, to be precise. I need to be able to get ahold of her for reasons, I don't need to be able to call her in particular."
"Actually, what are you planning to do? I don't even know."
"I'm immortal, I kind of have to be," Cam tells Jenny, and then he turns to Emma. "You don't need to do anything else but send me home when it's time. This is a terrible circle so I am not attached or bound to you in any way; usually I'd be loaded up with safety precautions that I am too nice to need. I am planning to figure out what the world is like, and then come up with something useful to do."
"Can you make vaccines?" is Emma's first thought. "Or blood types, can you do specific blood types? Or plasma? Or- I'm sorry," she stops, scrunching back up as she sees people staring at her. A couple are grinning, and she squirms. "I'm premed, it's just... what comes to mind. I'm sure there's other things."
"...I can make those things. I can also make medical technology from the year 2159."
She has clearly caught no part of their previous conversation, or the aforementioned grocery list might start looking very different.
Emma had started to say something in excitement, but pauses at the reminder of how Cam will be trading for his apartment. "I- I mean, it would be so, so wonderful, if you could come to the hospital with me, I have work tomorrow, and anything you could make, but they just... I don't know how much they can pay you?"