-Ethan can easily tell when Sub's feeling by his body language
-Ethan has chubby cheek and Sub like to pinch them like a grandma would
-Sub is just slightly shorter, he'll kiss Ethan's chin by accident
-While both are mute, they can understand each other perfectly
-Sky got them together. Literally, with glue and handcuffs
-Neither minded
-It became worrisome when Sky 'lost' the key