Baby eridians, for a good portion of their lives, are soft-shelled, as Erid likes to call it. It takes a few molts (more than a few, but for abbreviation's sake) for their shells to entirely harden, absorbing minerals from around them and through their food to develop the shell on their exterior. If you need a comparison, consider how human bones fuse and we become less flexible as we get older.
But for a few years (cough, decades, cough), a baby pebble is about as hard as a soft-shelled turtle—or a normal turtle, if they're a bit older. Disadvantages aside, there is an advantage to being able to see your offspring's internal functions. And until their vocal bladders form and they're capable of making multiple complex sounds, being able to see what is hurting is absolutely helpful.
It's a universal experience among parents to lament the day they can no longer hear their pebbles' heartbeats.
That is to say, Rocky knows Grace is an adult, okay? He isn't someone who anthropomorphizes, and he isn't going to start now. Statement.
But when he first heard Grace in all his squishy glory— heart pumping away, lungs filling and deflating, organs digesting food— his brain went full baby-fever mode. Frankly, he was white-knuckling the urge to find the nearest hypothetical cave, bundle him up into a proper nest, and wait for his skin to absorb the surrounding minerals and start hardening properly.
But because Rocky is sensible and proper and not going to infantilize his best friend (he swears to God, stupid fucking instincts, shut the fuck up!!), he won't.
But sometimes the urge to squish his best friend is overwhelming. He just pinches at him through the permeable mesh of his ball. And Grace will screw up his face (so soft) and go what’s up bud? I piss you off or something? (He learns what bruises are and sulks for half a day afterward.)
All of that aside, once again, Rocky has gotten used to Grace's heartbeat, his clumsiness, and his one-tone voice. That's his best friend, and he's smart and just as capable as any other adult. He is also the cutest fucking thing to Eridian hearing. Is he also disconcertingly alien, definitely— His size, the limbs, the head protrusion (and other protrusions), the leakiness detracted maybe. But his cluster-sibling once cooed at and brought home a pet sulphur slug because, oh my spirits, hear his squishy respiratory system and you tell me that's not the cutest thing on the planet! It blurbles, Rocky! It fucking blurbles!
So, as Erid draws closer and Rocky/Grace become more excited and stressed. (The food has yet to run out, and as good as Erid is, they need substantial help from the human side to figure out how to make proper human nutrition. And finding the right informational packs in all of human knowledge is a very big undertaking.)
Rocky dreads the ever-looming talk he’ll need to have with Grace about the fact that Erid may, in fact, possibly find him very, very adorable. And that this might hamper communication for a second while he explains no, that is not a tall baby and no you cannot squish it.
