I see your “Rocky swears like a sailor but only in pitches humans can’t hear/refuses to teach Grace what those words mean” and raise you “Rocky swears like a sailor and now has to explain to Grace that ‘bad bad bad’ isn’t actually a sequence you play on your Eridian speech piano in polite company.”
Grace is both horrified and amused to realise that a more accurate translation for what Rocky’s been saying is “shit shit shit”.
Eridian government representative: Greetings Rocky, Saviour of Erid, and Grace, Saviour from Beyond the Stars. We are pleased to welcome you home.
Grace, haltingly on the keyboard Rocky built for him: Wassup bitches. Fucking jazzed to—
Rocky: GRACE STOP TALKING NOW NOW NOW I EXPLAIN LATER
Grace: "Huh? Rocky, are you switching languages on me? I don't know any of those words! Please, I'm trying to make a good impression on your people!"
Rocky, in dawning horror, realizes he can either 1) continue speaking polite, non-swearing Eridian and have Grace not understand his warnings or 2) he can repeat his instruction in the language Grace will understand, and every Eridian in earshot will understand exactly where the alien learned his potty mouth.



















