In the Orbit of You, by Ashley Schumacher

When they were little, Nova and Sam were inseparable playmates.  They played with snails in the backyard and styled themselves as the King and Queen of Snailopolis.  They planned to be friends forever, but Sam's father was hurting him and Sam got taken away.  And then Nova and her Mom moved away as well.

Moving is a big constant in Nova's life.  Thanks to her Mom's job as a consultant, they have to pull up stakes every few months.  When she was younger, Nova liked the excitement of going to a new place and having a new beginning, but as she grows older it has begun to wear on her.  Not only has she been unable to form any lasting friendships, but also she has struggled to develop any sense of herself and who she wants to become.

The latest move seems like all the others until she stumbles upon Sam at school.  At first, he doesn't recognize her, but thanks to a gimmicky personality test the students take, he is drawn to her when they are matched as "99% compatible" (much to the chagrin of Sam's girlfriend Abigail).  After the initial shock of the reunion, they agree that they will just be friends.  Nova will be moving on in two months.  Sam has a good thing going with Abigail.  They agree it is better to stay "on course." But of course that isn't what ends up happening.

While the idea of destiny and fate can seem very romantic, there is the hanging dread of eventual discovery as Nova and Sam start fooling around that weighs heavily on any of the fun.  And with Abigail portrayed as unusually nice and understanding, their betrayal seems cruel and selfish.  In the end, Abigail herself rightly calls them on their immaturity and I was left without much sympathy (and even less empathy) for Nova and Sam's angst.  It doesn't help that the story gets dragged out far longer than it needs to be.  The subplots about Nova and Sam's individual struggles with their futures would have been far more interesting with less of the secret forbidden romance (maybe without any of it).