For me it would be a prolonged (3+ hours) CNC milking session. One or two women with toys (wand, milking machine, ..)
The kink really is about feeling abused past the point it's fun or enjoyable, with or without erection. I've had it in the past but never beyond 1.5-2 hours.
I feel like I'm getting closer to plan it as I've had fun sexting with some SPs who could be into it. It does require trust that she can both go thru with it but also respect preset boundaries as well.