One guy uses his fingers, nails, or a feather to work another guy’s ribs, pits, belly, feet, or inner thighs until he’s squirming and laughing. It often plays like playful domination, with pinning, restraints, and a lot of teasing touches that blur into groping, hard-ons, and eventual sex. Some scenes lean meaner, where the helpless guy gets tickled until he begs, cries, or cums from overstimulation.