Disclaimer: This is a photo-manipulated crossover, and I do not own the characters nor the screenshots mashed together.
Story of the picture: Panty Anarchy and Dib Membrane had a night out where they eat at the pizza restaurant at Crapsack City and drink too much cream soda and have themselves a good time (even if they didn't talk to each other often) to the point where they both go to the same bed together. The next morning, however, Dib was in confusion and shock that he was sleeping with the girl he didn't know much about.
...You may imagine what will happen next to them, because what could possibly go wrong? (SPOILERS: Everything.)
Dib Membrane belongs to Jhonen Vasquez & Nickelodeon.
Panty Anarchy belongs to Gainax.