It seems like Shatter (the red Pegasus) dared Slipstream into doing a challenge and that was, trying to hold in their waste as long as possible after consuming diuretics and laxatives, Slipstream (purple Pegasus) was willing to do the challenge, so they did. But Shatter had the two of them wear diapers just in case one of them lost and had an accident. Here, it seems like they’ve been holding it for awhile, Slipstream acting desperate now, but Shatter acting her usual self, but in her mind, she’s regretting her decisions and actually suffering just as bad. Hopefully, one of them wins, but…That may be unlikely, however..And for the fact that they’re trying to do this as long as possible so basically, for several hours or a day even.