@Vec I think the current extent of hain mating details is limited to a picture of a nervous anime girl saying "snake cloacas" with a chronic stutter.
I think I'll go with 'bird like,' point to their biological draw towards polyamoury, and leave the rest to the imagination.
Something else to consider is that Majus' mating habits haven't been documented either. I've spent five minutes thinking about this and decided that no one would have the patience to walk Majus through the process.
@Cyclone Sort of and they do have other worship. That's got a longer answer that I will give you when I get home from uni today. Sit tight.