What is a ruined orgasm?
Ruined orgasm is a typical play in BDSM. They are orgasms with stimulation purposely ceased as part of tease and denial play. The male submissive is stimulated to the very jag of climax until stimulation is abruptly stopped.
For a Domme, ruining their submissive's orgasm reinforces the control they have over their submissive by deciding when they actually get to experience a full orgasm. And for the Sub, many enjoy the intensity of the tease and denial elements that come with their owner domme's commands.
After having their orgasm ruined, the Sub can still maintain their arousal and use their feelings of frustration during some post-ruination sex*. Dominants can toy with ruined orgasms as a way to frustrate their Sub partners to the point of really savoring that final full release in which they are allowed to feel all the climactic pleasures.
How to do a ruined orgasm?
The domme starts with a hand or foot stimulation on the sub's cock and build up the erotic tension. Once he is super close to the point of ejaculation and desperately begging his domme for an opportunity to cum, the domme stops all the stimulation.