At the risk of echo the previous comments, I found the plot too light and the gift of the main character underexploited. Why put the shadows in the foreground at the beginning of the novel out of history after 70 pages? Why not use it again on his return, adult, at the resort? Why not involve them in the outcome (it would have been so charming)? Moreover, the outcome is confused and sloppy. It would be interesting to know more.
Exchange girlfriend friends shocked me a lot. The author, I appreciate also present this as normal while it is clearly unhealthy.
In conclusion, I would say this novel gives the impression of having been written several times over a long period. Generally, when the author introduces an idea or even a subplot, it ends up back on it. In this novel, this is not the case.