I think that he will ask her and she will tell him, and this is where the name "Only I know" comes in as he tries his best to protect her true identity. His actions bring them closer together, they fall in love and everything goes well until the happy ending
This was a good final chapter. It didn't need a forbidden romance, but with the last words there might be a hint at a future possibility that we will never see.
Very good series, I enjoyed it.