As far a rent-boy/professor May/December story, this one just felt 'okay' to me.
I liked Nathan -- I liked that he didn't wallow much of his profession and Nathan was determined to get his A-level and studied because he wanted to be a librarian (awesome dream, Nathan!). Since this story was written from his perspective, I got a full-fleshed perception of who Nathan really was.
Unfortunately, I also felt lack of emotional connection between Nathan and Stephen -- in fact, I felt more connection happening between Nathan and his college friend, Siobhan!! Stephen felt distant to me, and even after half-way through this novella, I still didn't believe that Stephen felt something for Nathan. Unlike Nathan, who definitely liked him. So it felt unbalanced and I ended up not believing in them much.
Thus my 3-stars.
It was rather angst-free for a rent-boy story, even if Nathan was horribly beaten.