"nerds"
@noelle Spouse and I call each other "nerd" and "dork" all the time, almost always while laughing, after one of us has made a terrible pun or done something silly. it's definitely a term of endearment between us.
the only other time I hear it said out loud is over a D&D gaming table; when the person who plays a tiefling bard that sired a half-doppelganger is calling the person who plays a half-orc barbarian that's suffering from a god-curse "nerd," you know nobody's taking it seriously.
"nerds"
@noelle on the other hand, I never had it used against me as a serious pejorative in the past; if I had, I might well be less casual about using it now. and I'd never use it with somebody I didn't consider a nerd-buddy, or somebody who wasn't ok with it.
so for me, being greeted that way by a stranger doesn't set off any particular emotional connections one way or another. (isn't very helpful in this conversation, sorry)