Noctis can do something to soothe Nyx. He is doing something. Letting Nyx fuss and hold him and kiss his hair, his cheek, nuzzle into his shoulder almost like a big cat aggressively scent marking their mate. It as much soothing as he can get. The fact that Noctis hasn't said who it was yet makes Nyx thing he doesn't even know the guy either. Not too surprising with how new Noctis is to the simulation.

"There's stew too but make sure you can swallow that alright before you try something heavier."