Thanks will have a look at some of those. We do actually just have a cuddle and normal sex quite often and then have a few nights a month doing the above.
1) (Both sexes) Stopping all touching justttt as the person tips over the point of no return
2) (Both Sexes) Slapping the penis/clitoris as the orgasm is happening
3) (Men only) Squeezing their penis tightly as they orgasm (Not pleasant)
etc etc.
Why would you ruin one? Sounds counter-intuative doesn't it hehe. Well, ruined orgasms are often used in tease and denial/chastity/power dynamics type play. They are either used as punishment, given to a male to "milk" him without giving pleasure (So his urges drop but he got no pleasure in it), they can happen accidentally to someone edging w/o permission to cum, others being denied for a long time may consider them a rewardt and for some they are actually more enjoyable than full orgasms (its a psychological thing....the thrill of being denied, of someone taking control of your pleasure etc)
Sensory play with: Candle wax, ice cubes, feather ticklers, wartenburg wheel, hoods (for sensory deprivation etc), flavoured lube, tingling/warming lubes, a flogger, blindfold, hair pulling, scratching, biting, dirty talk, sensual massages, cock rings...basically anything that heightens or changes the sensations felt, or adding new sensations.
Double penetration: either a bum toy while you penetrate her vagina (or a vaginal toy while you penetrate her bum), a double ended dildo that you can share or a couples toy, like the we-vibe 4.
I also recommend tease and denial, but then I would because I am a huge fan of it.
A ruined orgasm occurs when all stimulation stops just before the first burst of ejeculation. If done properly the cock will twitch and fluid/ ejeculate will run out but it won't 'blast' out as in a normal orgasm.
This leaves the man even more fustrated and horney than when you started even though he does ejeculate.