After I filmed this, I looked closer and saw the evidence of their love. Little eggs all over the side of the pond, and also all over the top of the water lily's pot.
The bees are having a busy weekend, too. They are bringing in pollen like nobody's business. It's hard to see, because they move so fast, but pay attention to the one bee that lands on the cinder block, near the end of the video. Look at her hind legs. See the pollen?