I love to hump on the soft shiny seat of my riding lawnmower. I straddle the seat, grab onto the steering wheel with one hand and the soft vinyl seat with the other. Using saliva for lube I hump away as my balls are stimulated by the gear shift knob.
I have an old bike with one of those soft shiny 'Banana Seats'. I lube the seat with baby oil, tuck my cock between my balls, lean forward, grab onto the handlebars as I slide back & forth, up and down & side to side. I quickly reach massive orgasms!
Leather & vinyl chairs, barstools & car seats are awesome to hump on too! Anything soft & Shiny. Ladie's shiny black patent leather shoes and purses have given me awesome orgasms!