The foals have been keeping apart since they were born, sensing the competitive distance that their mothers have kept between them. Now, finally, as the mothers are more settled, the foals have begun to play together. They are great fun when they are together. The foal fun only lasts a few minutes at the moment, then they return to the protective distance that their mothers impose on them.
At one point early in the video, Matilde arrives to call Aitana back from playing with Morris. Then they get together again while Matilde and Rubi are engrossed in their evening feed.