You may look at these photos and think (as I did initially) that it is two elephants mating. But it’s not. Our guide at Wild-Eye explained that it is actually a dominance display from one bull elephant to another. He said that males will usually practice this behavior especially when swimming in large bodies of water as a form of playing and showing dominance.
The elephant being dominated was not happy and once he broke away he chased anything that got in his way . . . cape buffalo, zebras, gazelles, birds . . . He eventually went back to his herd.