horseback riding

I am a straight female, 25yo. My girlfriend invited me to go horseback riding a few months ago. I hadn't ridden in a very long time. The first thing I felt was being in the saddle and feeling a tingle between my legs. Omg I was getting turned on I realized. Within a short amount of time I bit my lip and climaxed. Thankfully my girlfriend was up ahead of me and she didn't have a clue I was in the middle of an orgasm. This happened once more before we returned to the stables, my panties were soaked by the time we got back. Every time I talk to her I'm hoping she will invite me to go riding again with her.
Has this every happened to any other girls?

I used to love horseback riding. Every time I did it I'd have multiple orgasms. Miss those days....