From award-winning Carolyn Mackler, the story of Willa, who has been living with Sensory Processing Disorder but is thrown for a BIG loop when her dad announces he's dating Willa's best friend's mom.

Willa likes certain things to be certain ways. Her socks have to be soft . . . and definitely can't have irritating tags on the inside. She loves the crunch of popcorn and nachos . . . but is grossed out by the crunch of a baby carrot. And slimy foods? Those are the worst.Willa can manage all these things -- but there are some things she can't deal with, like her father's big news. He's been keeping a big secret from her . . . that he's been dating the mom of Willa's best friend Ruby. Willa does NOT like the idea of them being together. And she does NOT like the idea of combining families. And she does NOT like the idea of her best friend becoming her sister overnight. Will she go along with all of these changes? NOT if she can help it!