Hi, Lin. I'm the DGer that told you that the fungusy thing you were seeing was the wilted flower and that you had missed the show the night before.
Before that I didn't even know that they bloomed. But noticed the wilted blossom looked like my night blooming cereus' wilted blooms. So I googled it and made a comment to your post. I'm still waiting for mine to bloom. It's not as huge as yours and I have not been taking good care of it. But now that I see the photo of your blooms, it's a reminder that I need to get back on track and feed that plant.
I lost my NBC several years ago due to a serious illness. I do miss seeing it bloom and the wonderful fragrance. The first time it bloomed, I went out several times during the night to take photos. I was so excited, I woke up and dragged DH outside a couple of times that night to photograph & watch the show.
The next year, I got smart and brought the plant in the house the night it bloomed and took a round of photos. I need to find those photos. It's a fun process. Yes, do take photos and enjoy the blooms.