I've seen guys discussing things regarding escape challenges somewhat frequently; fail to get out and you get spanked *hard* two dozen times, be put in a predicament bondage position for 30 mins after if you fail, etc. For those who have had the good fortune to try the ErosTek 312 box, this opens a new potential for such a scene.
I'm pretty big on mindfucks and legitimate control as opposed to fantasizing. In lieu of some vague threat that takes place after you've been too distracted by how hot the position you're tied in is, imagine under a pair of chastity shorts you have some bluebands on your cock/balls and sticky pads on each cheek. The box is placed far out of reach and set to a ramp-up setting over 30 minutes getting up to 70 when even 50 is uncomfortable for you. For the first 10 minutes you struggle just for fun with a raging hardon because of how well you're restrained, not really wanting it to end. By 15 minutes the shocks and jolts start to have you grunting and protesting, but your captor just kicks back and watches as you writhe. By 20 minutes the intensity is enough to have you legitimately fighting against your bonds, but you've wasted so much time that the now intense jolts keep you from concentrating on your escape.
Ten more minutes roll by, seeming like hours, and the intensity is now almost unbearable. You're panting heavily during the troughs and it's taking so long to recoup after each jolt that you're only just starting to try to untie yourself again as the next jolt comes. Your captor's still sitting back and watching, and it's suddenly very apparent you're not going anywhere for a while as your face contorts in hopeless agony.