When we ventured that Igor Zeinalov's version of Leda and the Swan was the only rear-entry interpretation of the myth that we had seen someone commented that there was also a similar approach taken by the American artist Fred Einaudi (b. 1971) in one of his paintings.
It is difficult to discover much about Mr Einaudi, other than he lives in San Franciso, but his surrealistic paintings are largely fixated with images of death. His Leda, ecstatically being ravished by the Zeus swan from behind, shares her environment with a wrecked boat and an artist (a self-portrait?) on a bleak looking beach.
I suspect this may be an early work as it is not as technically accomplished as some of his other paintings and the composition piles up the key elements (Leda, swan, artist, boat) on top of one another without much regard for depth. Still, an interesting interpretation.
More of his work here.