Consider this; Grace rescues Simon from the blood ocean but because of the attack from the Blood Eel he temporarily damaged his vocal cords along with the other many mutations he went through. Because of this Simon can’t speak so his mutations kick in and he’s communicating in an odd language of clicks and growls and chirps, with his appearance added along with that, Grace assumes he’s another kind of alien species.
Sometime after the canon Simon FreakOut, Simon realized that he can use this to his advantage in an attempt to court Grace.
For Example:
Rocky: Grace spend too much time with Simon!
Grace: Rocky, we’ve talked about this. Simon is very clearly a species where he needs skin to skin contact on the daily or he doesn’t feel well
Simon, literally holding Grace on top of him: *in eel speak(?)* ~yep, totally need that. It’s not just cuz I get crabby when you don’t cuddle me~
~~~
Grace, thinking aloud: your species must be such social creatures! I can’t imagine a whole planet filled with people who have the need to cuddle daily!
Simon: ~Yes…social creatures…~
~~~
Grace, seeing Simon wearing the harness: oh! Is that a cultural thing? For modesty? Would you be more comfortable if I wore one?
Simon, quite literally foaming at the mouth at that idea: ~YES PLEASE~
~~~
It’s even better if, for whatever reason, Rocky can understand Simon’s eel language but doesn’t say a thing because Grace clearly needs the contact that Rocky can’t provide
That doesn’t mean he’s happy about it, though
Rocky: Simon hog Grace, statement.
Simon: ~Cry about it~
Rocky: *rolls over his foot*
Simon: ~You son of a—!~
~~~
Rocky, watching them cuddle* Simon is little baby
Simon: ~I will kill you~
Rocky: Rocky like to see Simon try, statement.
~~~
Grace, watching them talk to each other while Rocky had turned off the translator: I wonder what they’re talking about, maybe their species can become friends!
Rocky, to Simon: Little bitch boy!
Simon: ~stone faced little asshole!~
Rocky: Clingy sad man!
Simon: ~Jealous rock head!~
Rocky: Ugly fish boy!
Simon: ~WHAT DID YOU JUST CALL ME?!?~