[Cerberus is definitely happy to see someone he recognizes and he pulls away to bound back and forth between Percy and Nico, as if to say 'Look what I found, Nico, look, look!'

Nico doesn't even protest when Percy gets him in a headlock and gives him a noogie. He's too busy trying to stop his eyes from watering. Finally, after months, he's not alone anymore. He pries his way out of Percy's arms though so he can get a good look at him, using his sleeve to quickly wipe at his eyes. I... Annabeth is here too? Cerberus came in with me, Mrs. O'Leary didn't so I don't think she's here... [He's trying not to let his voice crack as he talks, mouth quirking up into a shaky smile.] He's definitely destroyed a lot of rubber balls, yeah.