It was a common myth as a kid.
that riding a horse for women increased their clitoral activity as the rhythm of the horse and saddle engorged their sexual labido
Having ridden for years, I can confirm that I felt I'd starred in a FAB straight porn movie, and had my balls put in a flower press after a few hours in the saddle.
Nope I have ridden horses for years both as a job and own horses and I can safely say I have never had any sexual thrill from riding them. Lol To me anyhow it is definitely a myth.
I know the first time I rode a horse, when it cantered I felt my nadgers bouncing up and down and being squashed underneath me. That was definitely not arousing.