This is what I've been trying recently:

My girl is very suggestible to things I say when she is sexually excited, so I try to use rich descriptions. It is very effective.

I discovered that if she starts cumming a few seconds before I feel like I'm going to come, I can tell her, "Keep cumming, I'm going to come soon!" and her orgasm will last another 10 seconds.

Having a good commanding voice tonality is important here.

I also found was that I don't even have to come for it to work. I was railing my girlfriend, it had been about a week since the last time, and I wanted to make it a good experience for her. When I felt her pussy start to flex, I just command her, KEEP CUMMING! When it starts to abate, I tell her again, KEEP CUMMING!

I did it seven times yesterday, she said she had like waves of orgasm flowing over each other for about two minutes, it was incredible.

Let's all give some women the fuckings of their lives...

I have tried this and I highly recommend it. I was a bit skeptical but it works with hard deep-spot stimulation. Mind you, this HB could already stack her o's.

Hrrm that's some good advice i'm going to have to try that next time. I've tried this one a couple times see if it does anything for you, if i think i'm getting close and want to make her squirm a little bit i'll command her not to cum yet and to hold it and start goin harder. If I think she's gonna have an orgasm i'll command her again to until i'm ready then tell her and she always has MASSSSSIVE orgasms simultaneously with me

going to give this a shot..