Whether you choose to tell your friends about your chastity arrangement or not is irrelevant.  His wondering about how much they know is a great thrill and tease.  Make sure you wear your key on a necklace to add to the thrill

Make him repeat this often.  Making him do this while you are topless works wonders for his motivation.  Punish him for dropping his gaze to your breasts without permission

improve his Tongue strength and creativity by making him trace letters with his Tongue pressed against your pussy.  For example, trace, "yes Mistress".  Find phrases that are especially pleasurable, and Make Longer phrases, to keep him busy. Don't forget to discipline, if he's not doing it perfectly.  :)

Keep him in chastity while letting him wear a strap on.  His attention Will not be on his release, but your orgasm.  The teasing is delightful!  The humiliation of him feeling the same motions, but using a substitute tool is beautiful

When you have guests over, dress just enough mistress- like to keep your man's attention, and keep him nervous.  Dangle something that looks a bit like a whip...  Your girl friends may notice how strong his devotion is to you!

While he is in a submissive state, walk around in his view letting your strap-on remain prominent and very visible.  It is an immense power trip.  Yours can remain erect much longer than his, and the suspence will drive him crazy.

Real love is making sure there is only one woman controlling a man's cock.  Only way to ensure that is a chastity cage.  Refusal is not an option