A few years ago (not in the last two years but after 2010) I read a young adult science fiction romance in which a human girl falls in love with an alien humanoid boy.
The part I remember most vividly is in the beginning, where the girl sees the boy arrive naked in the forest (although in my memory it is the boy who sees the girl). If I am remembering correctly, one of them is across a river or creek from the other, and remains unseen.
Later the same person sees the other (in school?) and recognized him (or her). I believe the novel was made into a movie or tv show, but I may be confusing the book I read with a similar story.
The important part I'm after is the beginning in the forest. I thought the title was Star Crossed or something like that, but I guess not.
After some research, I suspect that the book is Obsidian by Jennifer L. Armentrout, but I cannot find a preview that goes far enough into the book to show the forest scene.