(you'll have to excuse me, my mind sometimes works in strange ways, and this is what it came up with)
The hoya was ready. It was healthy, had plenty of food and lived in a humid environment. It produced big and beautiful buds, which were now ready to open.
It started opening its buds, peeking into the new world, in the morning, getting ready for the evening. As the day wore on the buds opened up fully and the hoya started to make nectar to entice its visitors.
By the end of the day it was ready. The hoya produced the sweetest smell and nectar to entice the moths to come its way and to take its pollen off to another hoya so that it could produce seeds.
But no moths came, because the plant was inside.