Rarity’s fear wettings continue!  
A little slip-up during the rock-wall climbing activity has the fashionista instantly positively flooding her knickers in fear of falling!  
Applejack can only clutch the safety line and stare in shock as her (not-so-)secret crush voids her (apparently very full!) bladder into her fancy shorts, the farm-girl’s face growing suspiciously hot… ;)
 
A “sound effect included”, as well as a directly shipping, “Applejack likes this” versions available at the pixiv source link.