Eeeh, I think it was just kinda thing that lots of like nomad ppl were thought to do, or may be they claimed to do
I think it was meant to make them look super ferocious and like wild too
Like think about Mongols and tribes like that
They spent like all their time on horses, they could like stand on riding horses while shooting from a bow
Wouldn't be suprising if other would think they do that on a horses too or they might have said it to seem like crazy barbarians
Oh, and like everyone thinks anyway that woman riding horse looks like when she's on top of a man
Also, I think if it were actually to happen on a horse while riding, it was not meant to be safe or pleasurable for the woman
But obviously that's not in the way he implied it here, so let's not talk about it

Why is horse back riding sex a trope I see sometimes? I just don’t understand how that would work without hurting yourself