Twilight Sparkle is playing soccer against Rainbow Dash, but getting near her and smelling her causes her to hit herself in the head with the ball, as Rainbow Dash hasn’t washed for over a week.
 
Just another Smelly Rainbow Dash pic. If you don’t like the concept (or edited screencaps), please ignore, they’re not meant for you. (That’s why I put Suggestive tags on it) Answering the request of someone who likes this kind of thing.
 
Maybe I went a little overboard with the visible stench this time. Just wanted to put it on the three most smelliest places: Her armpit, her shorts, and her feet.
 
I cannot stress enough that I do not think she is like that in canon. At worst she’ll smell a little sweaty after a game or something (or performing hard onstage in the heat of stage lights to the point that even her hair is soaked with sweat) and she’ll probably wash either that day or the following morning. I just like to fantasize.