A little more text on my Tumblr.
 
“ Y’see every so now and then Twilight has a day to herself. Spike is either flirting with Rarity, or at the book store with Rainbow Dash, and Twilight is left to her research and cleaning.. As far as anyone knows.
 
 
Twilight seems to have developed a fascination with pee holding. Consuming fluids periodically until she is rendered almost motionless on top of a layed out diaper for easy clean up. As she waits for it to get more and more intense she reads one of her limited edition hardcover omorashi books featuring pee models from all over Equestria.
 
After she starts to loose the fight, and a deluge of pee escapes into the diaper she gets very excited and rubs her crotch titties into the diaper and orgasms to exhaustion. Sometimes she goes overboard and has to wash her blanket as a result.
 
Little does Twilight know Spike might be away, but Owlolicious is very confused.”