"Purebloods are probably more likely to find the concept of free elves inherently hilarious."
"You might be able to meet an elf if it would make you feel better by leaving a note with your laundry."
"Um, and I could look it over for you so you don't accidentally insult them or something."
"It's not like we have one, but we might know more people who have them, I guess."
"I think it's probably faster to talk to Hogwarts' elves, but if that's a dead end I'll ask."
"Oh. Yes, that'd be very good. Any suggestions? I mean, any reason why just going with 'Hey I'd like to talk about potentially unpleasant topics with a House Elf, I am a muggleborn and therefore likely to accidentally offend you so send someone with a tough skin' or the like wouldn't work?"
"Maybe something like 'I've never met an elf before and want to ask some questions, if there is anyone who isn't too busy' and let them fill in the blanks."
"I feel like it's kinda misleading, when I know I'm likely to offend them or some such, not to tell them that upfront. I mean, I'd feel misled if I were in their place."
"I mean, you could try saying that you might offend them but I'm not sure there's a polite way to say it straight out, especially when you're already in the situation of only wanting to talk to somebody because of their species."
They finish eating.
"I'm going to the Library to check out a couple of books on Transfig Professor Robledo suggested, anyone wanna come?"
"No thanks, I should probably manage to do more than silvering up my matches before picking anything new up."