Blowjob tease and denial: girl is blowing his cock like a pro but not allowing to cum again an again
Mistress is using balls destruction as a way to stop that man from jerking off: spread-eagle bondage, balls beating and trampling are doing the job fine
Guy got his cock in the glory hole but girl bondaged it with thin wire instead of giving up a blowjob
The worst femdom tortures you can imagine: hitting weak penis with mouse trap and then cutting off balls with castrating device