Here’s Google Translate, for all it’s worth.
 
SD: my mushroom plane full of eels
 
SS: What?
 
SD: I will not buy this recording is scratched
 
SS: It seems to me that you are trying to speak my native language
 
SD: if you let me order the clam chowder, we’re all going to have chicken pox in the morning
 
SS: In English please. Your Spanish is incomprehensible.
 
SD: Oh, thank you so much! It’s much easier to communicate with your pony counterpart! Because she’s from Equestria like me and you’re from Argentina.
 
LOL, I did not get the joke until after I added the last line following the pasted translations. Argentinian Sunset must be just as confused as when this conversation started.