Aleuts are a different group, of course I'm not lumping them together.

https://www.uaf.edu/anlc/resources/inuit_or_eskimo.php

Your stepbrother-in-law is, of course, entitled not to be offended by it, but on the public internet, you will almost certainly run into people who are. (Also, the entire "This one person gives me permission to use the word" thing is not a good look for us white people).