Alternative title: Unfiebelle.  
Dunno why, but this idea spontaneously came to me during the stream and I had to draw it. I REALLY don’t know why. On a major unf streak lately.
 
[+Scootaloo fluttered her little wings as she struggled to hoist Applebloom up to a window.  
“Can you see her yet?” the orange pegasus asked through a grunt.  
Applebloom lifted her head up into the open window to peer inside.  
“Yeah, Ah can, and… Oh mah.” Applebloom immediately scrunched.  
“What? What is it?”  
Inside was Sweetie Belle’s bedroom. And on her bed, the white unicorn sat. A clear view of what hugged her lower bits was on clear display to Applebloom, and it wasn’t clean. The sound of squishing and soft crinkling quietly filled the air…  
“Nnnf… I can’t let the girls find out about this… My place as a Crusader would be ruined…” Sweetie Belle whispered to herself as she rubbed the front of her sodden and filled diaper.  
Applebloom watched Sweetie Belle’s left hoof move up and down in a rhythmic motion as she drew steady breaths. Every now and again one of her hind legs would twitch in pleasure.  
Scootaloo looked up at Applebloom. “Well? What is she doin–”  
She was cut short by a drip of clear liquid splashing on her nose.  
“Gah! Applebloom!” Scootaloo shouted before collapsing, taking Applebloom down with her.  
Applebloom gave a nervous chuckle. “Sorry… She was uh… Well…”  
Sweetie Belle stopped cold as she looked at her open window. Her heart skipped a beat. Was… Was someone spying on her?  
Applebloom and Scootaloo ran off before Sweetie could reach the window.  
Sweetie Belle feared the worst.+]

imported from https://derpibooru.org/images/1083054