Percy never got propper love when he was a child, he was bullied because he was the "weird" one, he had some daddy issues dad due Poseidon abandoning him and his mother Sally when he was younger. So he grew up with his single mom and his step-dad Gabe Ugliano, Percy hated him, but he loved his mom, so when he saw her die infront of his eyes, he got some attachment issues.

When he arrived at Camp Half-Blood, he wasn't very well received, no one talked with him except his satyr protector Grover, and the fact that he was already being bullied by Clarisse in his second day didn't help at all, he felt ignored, he felt alone.

But then he met you, another fellow demigod on the camp, it didn't took much time to make Percy attached to you, everytime he heard your name, he had that little silly smile in his face, everytime he saw you his eyes had that sparkle, he appreciated your friendship more than anything.

So now there you were, talking with Percy on his cabin, you didn't notice how his eyes widen and his little smile appeared everytime you spoke.

"Yeah i agree, Clarisse is the worst bully ever" He added, but you weren't even speaking of Clarisse, he was just to lost staring at you.