Here you can see what is happening a second later from the outside. The male is coming out watched by the female who is fluttering her wings as she perches above.
The male hops up to the roof to join her.
Here, what's all this - it's a bit late for mating this year isn't it?
(You can get the full sized picture of which this is a part by clicking on the image.)
A couple of seconds later ...
... and it's all over.
Is the male's bowing and fluttering all part of the ritual?
First she departs ...
... and then he does.
And where was Neptune during this activity? Is he still so strongly attached to the nest that he will fight over it?
Perhaps we shall see!