I really enjoy stories and art about a "victim" who's inflated with so much helium (or other lighter-than-air gas) that they start to float. Especially if the victim is (or gets taken!) outside where they could be at risk of floating away. I don't know why, but for some reason the dominance/submission in that kind of situation really fascinates me, where the victim's tormentor could let go at any moment...
Anyone else with similar fantasies?