People watch James in pubs; lads and lasses both. James never notices them.
Robbie always notices. At first he's amused by James's obliviousness. For a detective, he's surprisingly unobservant about personal matters.
Then, Robbie's sad, regretful. James must be lonely, must need to touch and be touched, but he never notices those who could be what he needs.
Now, Robbie is pleased by their attention. Let them notice the lad's lean, strong frame, the tilt of his head when he's saying something clever, his laughing eyes. It allows Robbie to exclaim (if only in the privacy of his thoughts) Mine!