Some of the men I've talked to get a little aroused at the sensation of rope or twine around the cock. From what I read, it slows the blood flow and increases sensitivity in the penis.  Keeping it realistic, instead of doing it all day, why not do it for a single class period? Add a cock ring, some twine, then stuff his cock back into his boxers and pants, then let him take the agonizing walk back to class with a hard boner rubbing against the inside of his clothes. Maybe he keeps the erection through class, supplemented by the promise of release or a little fun after the class, then has to take the walk back to get his reward. If this doesn't work, we can think of something else.<br/><br/>I'm not too fond of the remote earpiece or broadcasts though. It seems a little far fetched for the two of them. The chastity device would be a form of long distance control, and like you said, they could text or call him.<br/><br/>Your format for scenes sounds good. After the initial scene in the office, we can just sort of do "Several weeks later..." and set up a new situation.