The female here is doing a nesting wriggle - normally a sign that things are going well.
Box2 is looking quite promising with both birds frequently visiting.
The bird in the box is the male. He has crouched down to keep out of the female's way as she comes into the box. He doesn't look particularly welcoming to me. His beak is open as it would be if he was angry, but perhaps this is just a welcoming chirrup.
No sooner has the female landed ...
... than the male departs - no hanging around here.
Another nesting wriggle.
This is the male again. At least with this pair it is easy to tell them apart. Often you can only distinguish the sexes by watching how they behave.
The male is watching to see if his partner is going to come into the box.
He hears her outside and crouches expectantly.
In she comes - she is at the top of this picture.
The male departs straight away leaving the female alone in the box.
The male again.
The male looking out. He looks quite a smart bird - much smarter than his rather scruffy partner!