I tested out some methods.
Remember to breath! I had to constantly remind myself to take deep breaths. And women like to her you breath heavily(they like to hear you moan, but I feel ridiculous doing that).
Flex your abs as hard as you can. It distracts your mind a little, and I've read it draws some blood away from your boys, allowing you to last longer.
Don't concentrate on your naked grandmother(or whatever). I read it's better to concentrate on everything you are doing OTHER than pumping her. It seems to work. I thought about her lips and neck and the blankets on her bed, etc. I thought about how cold her room was and how my ass was freezing. Just don't focus on the actual act.
And, wear a condom! They really kill the feeling. Plus, they can save your life.
That's what I did and she said she had multiple orgasms. I almost reached the limit once, but I stopped before the evening was cut short. After that, I thought I could go on forever.
I worked out good.