Whenever Piper and Annabeth were PMSing, Percy and Jason worked together to make them feel better. They got loads of chocolate, blankets, and romantic movies, and they'd all sit on the sofa together and relax until the dreadful week was over.
***
JIPERRRRRRR!!!!
And with much less enthusiasm: er, yay, percabeth.
Sorry, don't ship it. *sad face*
But I think this headcanon is adorable so yeah.
I'm indescribably hungry right now. Does anyone have a pie?