I would say in my collection the longest lasting flowers come from my Ariocarpus retusus. They lasted 6 days. I don’t have pics of day 7, but I’m fairly certain they still looked good after a week had passed.

Oct. 11

Most night blooming plants are a one time thing.

But funny story, my chamacereus opened up for the second
time , and fully today.

I was very impressed with my Parodia (Brasilicactus) haselbergii. The individual flowers lasted more than a week.