Are we there yet? - David Levithan

Two brothers travel through Italy and take a journey of the heart.

Sixteen-year-old Elijah is completely mellow and his 23-year-old brother Danny is completely not, and they can barely tolerate one another. So what better way to repair their broken relationship than to trick them into taking a trip to Italy together? Soon, though, their parents' perfect solution has become Danny and Elijah's nightmare as they're forced to spend countless hours together.

But then Elijah meets Julia, and soon the brothers aren't together nearly as much. And then Julia meets Danny and soon all three of them are in a mixed-up, turned-around, never-what-you-expect world of brothers, Italy, and love.