If the photographer offered to photograph orgies then it would be discrimination if he refused to photograph one orgy simply because it was a Christian or homosexual orgy.
But as long as the photographer did not offer photography of orgies or of any other pornography, there is no violation.
You folks seem to not quite understand how this works.
I wonder what they think goes on at a same sex wedding?
I've been to two of them, both Lesbian weddings. So far as I could tell, they were typical weddings. One had a band, so I enjoyed it better than the other that had a DJ. the one with the DJ had better food.
But nothing about the affairs was the least bit torrid or shocking.