We shouldn't be doing this Step-Brother

When 18-year-old Sienna's dad remarries, she ends up living with 19-year-old Jaxon; her new stepbrother. He's broody, quiet, and always seems one step ahead. They clash right away, turning every little thing into a battle. But as tension builds, their rivalry starts to blur into something else. Something neither of them expected or are supposed to feel. And once that line is crossed... there's no going back.