Welcomeeee

Betty Cooper is the perfect girl next door with perfect grades and always styled perfectly you would say. Or is she really? She was, once, but after the death of her father it was like loosing her mom too, even if she was still there. But one day her moms behaviour changed, only for Betty to find out that her mom had replaced dad with a new lover. And not only this but her lover had a son, around Betty's age. And he was devilishly handsome.
So what happens if the two actually can't stand eachother but must live with eachother?