Love is love empowers young readers to celebrate the family they have-no matter how it's constructed. A boy confides in a friend when he's teased for having two dads and for wearing a shirt that they deem is "gay." kids tell him that they're not a real family, and he doesn't know how to respond.
But our narrator realizes that his friend's family (with a mom and a dad) isn't all that different from his: they both have parents who love them, and they both love their parents. And it's love that makes a family.