Interestingly, there are 3 adult Grey Wagtails around the nest site. I'm not sure what is the role of the 3rd bird? Perhaps it’s a young adult from last year’s brood, helping with this year’s rearing? I know some species have that type of familial relationship but I’ve no idea if it happens in Wagtails? Anyway, I was able to film the male last week, probably the mate of the pair. He sat in the sunshine and preened for nearly 2 minutes.
[The video is best viewed in 4K: press play then click on the cog, bottom right, and select 2160p4K quality]