Practicing ruined orgasms, orgasm on demand, and orgasm control. He should be lying face up on the bed naked with his Chastity Device off and his hands tucked under his buttocks or tied down so they cannot move.
You should be dressed in very sexy lingerie is sitting beside him masturbating him with one hand. You can even make him think you will let him penetrate you, but stop him at the last minute. The point is to tease him, making him think he’ll be able to cum, but to stop him from doing so and keeping him just on the edge.
Be ready to grab a handful of ice-cubes from a bowl full of ice to slow things down and ruin his orgasm just when he's on the edge.