To be fair, a lot of these alien peoples have means of communicating that aren't Standard (English? that's another discussion) and that in some cases even require means - physical or mental - that humans aren't naturally capable of reproducing. So a certain amount of "I'm just going to call you Steve"
would be going on. "Medusan" would be a useful descriptor, as long as they aren't offended - and maybe they're even amused by it, if they've been filled in on the reference, and if the translator isn't hiding that altogether.
The English speaking world has gone a long time calling Moskva "Moscow"...