Explain SMBC — the wiki for Saturday Morning Breakfast Cereal

This comic shows medieval dungeon torturers at work, with one torturer turning to the other and asking: "Do you ever worry that, hundreds of years from now, everything we do here will be used as a sex thing between consenting adults?"

The humor comes from the anachronistic self-awareness of medieval torturers contemplating how their instruments and methods of pain would eventually become repurposed for BDSM and kink culture. It plays on the real-world fact that many elements of dungeon torture -- chains, leather, whips, restraints -- have indeed been adopted as accessories in consensual adult activities. The joke frames this as the torturers' nightmare scenario: that their terrifying work will be trivialized into bedroom play, suggesting that the "horrible future" of the title is horrible specifically from the torturers' professional perspective, not from ours.