Women are constructed differently in this regard. After an orgasm for women there isn't the same dropoff of blood within the pelvis that happens with men. Women don't go into the same refractory stage that men do after orgasm. The vasocongestion remains within their pelvis so they can be restimulated much more easily. However, for some women once is enough.
Refractory equals loss of erection.
If it is something involving additional people, or swinging, I might make the recommendation that you both be on board about this one or invariably there will be problems. If it is a different position, you can compromise and sort of meet them halfway. If it's indulging in a fantasy, again compromise. Yet they've got to know if they push too far it's going to blow up. And if they are inconsiderate, that's not going to work.