Jason really didn't like visits to the mortal world. Jason really didnt like going to high schools to see kids his own age. And Jason really didn't like Percy being along on these trips.
Grover was long gone, off and away, probably munching through the recycling bins and not doing much demigod searching.
But him and Percy were allowed free entrance, under the impression of the Mist of two new students from out of state. They had a normal backstory, with normal parents, normal problems and normal lives. Everything was normal.
Other than Jason seething and boiling under the skin.
Every eye dragged up and down Percy's body, evaluating his hair, face and clothes. Huddles of girls whispered and stared violently, all giggling and pushing eachother like they were daring eachother to ask him for his number.
The reasonable voice at the very very back of Jason's head said they were staring at him too. But he wasn't listening to reason, he was playing with the animal instinct that made him do extremely dumb things around Percy.
The two stopped in the cafeteria and just watched from a distance. New students were fresh meat, but two new, hot, seniors were like gold in a high school. Jason placed himself behind Percy, watching over his head and shoulders, his arms crossed and a metal look etched on his face.
He just wanted to reach foward and put his arms around Percy, slot their bodies together and whisper things in his ear, make everybody know who Percy belonged to. Either they found the demigods and got out, or they were both leaving. The air was thick with jealousy.