Sure enough the couples are still sharing accomodation. In the top photo you can see the coot, at the top centre of the photograph on her tall nest. If you look carefully you can just make out a flash of colour to the far right of the photo, about half way down, which is one of the grebes (easier to see if you click on the photo to enlarge it).
In the second photo you can see the grebes who have nested precariously and unimpressively on the edge of the pontoon just below the coot's reed tower. Both sets of parents have been making use of all the litter to line their nests.