I recently read this article about John B. Calhoun's mouse utopia experiments that helped me finally understand the setting of Questionable Content:
http://www.mostlyodd.com/death-by-utopia/Questionable Content takes place in some Judge Dredd Megacity One enclosed future utopia where humanity's every physical need is met by an army of sentient robot slaves. Like Calhoun's experiments, most of humanity in the QCverse has descended into a writhing orgy of gratuitous violence, rape, and cannibalism. The QC gang are the "beautiful ones," who have separated themselves from the violence by channeling their frustrated energy into obsessive compulsive quirks.
That is why nothing ever happens in Questionable Content!
Now occasionally a violent savage will intrude upon their collective, like the Vespavenger, but these intruders are quickly put down by Marten's robot slaves. Eventually the screams and explosions in the distance will go silent and Marten and the gang will be the last remnants of humanity. Unfortunately, mentally broken by their utopia, they will never recover their instinctual nature and will not repopulate the Earth. I'd bet money that when QC characters say they're "sleeping together," they're being completely literal. When pintsize starts humping random appliances, he's not deriving pleasure, he's making a futile attempt to trigger the beautiful people's mating instincts, like a frustrated Panda keeper.
When Questionable Content finally ends around strip 5000 or so, the final image will be pintsize and all the other robot slaves in a bathysphere at the bottom of the ocean praying to a smiling statue of a blue fairy, begging her to make them real people, until their power runs out.