I helped my brother out on Saturdays taking his daughters to the riding stables, Judy 13 and Helen 15 at the time, on the way we'd pick up Clare 13 back then. The girls looked great in their tight jodhpurs, often Clare would sit in the middle of the back seat of my Landrover and put her feet up on the edge of the seat opening her legs, making her pussy bulge out of the tight gap between her thighs.
I would drive most of the way stiff as a poker looking at this young pussy bulging out of her jodhpurs in the mirror. Sometimes I would collect the girls, they were always hot and sweaty, Helen had great tits for a 15 year old and after riding, her nipples were like pokers sticking out of her shirt, I oftened wondered what the riding did to their pussies!
Of course these images keep me happy when I want to masturbate.