Put this on your amazon shopping cart or wishlist. Also save
machineyourself.com in your favourites. If your SO doesn't get the hints, drop more (like leave "machineyourself.com" on a note on your desk).
Or: ask your SO for such a birthdaypresent.
Or: just get one yourself. Tie hands behind back, blindfold and ride it for the duration of your 3 favourite movies playing in the background.
I dream of possibly losing my regular clothes while out in a park at night. Being forced to walk back to my car xdressed or naked and tied up or worse...