Animals other than the human generally don’t practice homosexuality at all unless something has upset their social system. These days, it’s usually something humans have done that upsets them.
(The only ones I can think of who appear to do so freely are dolphins and certain primates...)
They have two males in a confined space, not unlike a prison. I'm guessing it was a show of dominance by the larger male, and not some queer tryst gone awry.