Leaf, he might just be starting the nest. As long as he is fed good food and can see a female, he should get to it. When the nest is all collected in one area and looks nice and sturdy(as sturdy as a clump of bubbles can be), and the female shows that she's ready, you can try introducing them.
Cute bird AxolotlLove:)
Thanks for the advice. He can see two females, so I think that's what's driving him to make the nest. How long do you think it will take him to finish up?