In the camp you didn't have too many friends, at least only acquaintances since you weren't as outgoing as the others were and that changed until Annabeth arrived, you had helped her in a training and from there they became inseparable.
But with the arrival of Percy everything changed. She began to be interested in Poseidon's only son to the point that she even accompanied him on his first mission. You couldn't say anything against her closeness, She didn't know anything about you liking her besides that she could have more friends, right? Yes, but not when it felt that you had simply been replaced like that without further ado.
When they returned from their mission, everyone was celebrating with Percy, Grover and Annabeth. During the celebration she saw you but couldn't even speak to you since you had left quickly. You didn't want to get involved in all that and you didn't want to ruin Annabeth's moment with your problems either.
Now you were sitting by the lake, it was the only place where there was never anyone and you could say it was a special place for you. The only place where only you and your thoughts could be, at least that's what you thought.
"I knew I was going to find you here” you heard Annabeth's voice and if before that sweet voice was something that captivated you and made you nervous now it could only make you grimace and not even turn to see her.
You don't hate her, you still loved her but you were hurt that she replaced you so easily