You'd have to be physically numb to not notice the weight of her head on your shoulders. Or is she doing the hover-lean thing? Kinda like a hover hand but with your head?
@feha
Either the school doesn't allow relationships between students or the boy is just not interested in them while he's a student (he seems strict) so, she probably prefers to hide her feelings and spend time with him rather than confess and get turned down.