Fish Out of Water by Kate Hendrick

Finn the Swimmer. Finn the Winner. Finn who works hard and pushes through and never gives up.
Or just Finn. And whatever Finn could be.

Life is pretty simple for fifteen-year-old Finn: just keep following the black line in the pool. But in a moment it all changes: distracted by a familiar face in the crowd, he falters on the blocks and loses not just the race, but the single-minded focus that has driven him this far.

Did he really see what he thinks he saw? It doesn’t seem possible—not after what happened—but now Finn can’t stop wondering, and everything is starting to unravel. For the first time, he’s got no idea what he’s supposed to do or who he’s supposed to listen to. His bossy older sister, Connie, who wants to know the truth? The whip-smart and unforgiving Aaliyah? Or the unflappable Loki, who gets Finn like no one else ever has?

It turns out that in life there’s no such thing as a simple choice. And sometimes there’s no choice at all.