Orgasm control can be an erotically humiliating and gratifying part of a Mistress session.
The idea for this power exchange is for the slave to keep for a certain time an extremely high level of excitement and it is up to the Mistress to decide when and how her submissive can be allowed to have an orgasm.
Surrendering this control, giving the Mistress full power over that part of the sexual pleasure, and then the feeling of being allowed to finally have it can give the slave a huge feeling of pleasure and gratification.
A chastity cage or other bondage materials can be used in this practise and this can increase the feeling of arousal even more.
The time that the slave is forced to wait increases the excitement and his climax can result in an explosion of sexual pleasure.