@Master Fox, @Background Pony #5C72  
Fair argument. The idea is kinda cute too.

@Background Pony #EC13  
Me too thanks

@Liggliluff  
Well considering it’s a night gown, it’s not impossible for the whole outfit to be short. Maybe it was made with the idea of shorts being worn with it or even no concern over panties being seen.

@Master Fox  
Well, it would be an interesting design if it’s so short her panties are easily seen. – The frills are really tiny, definitely not dangling low. You can see a lot of the panties already. – One sensical idea would be that the skirt is a separate piece, and it had risen up on her body, as she’s been moving around.

@Liggliluff  
It’s somewhat hard to tell if it’s riding up or just short. Maybe the frills dangle lower. Also … The whole fact that the four are laying so close and yet, hiding from Applejack and Apple Bloom is so funny.

A really neat detail that Sweetie Belle’s dress is riding up. I guess that could end up happening in bed. She’s of course wearing very cute panties with frills around the legs.

@Background Pony #B05B  
“Crackshipping” is when the involved characters have never met in canon. Twilight has met all three of the CMC in canon, and interacted with them.
 
As has Rarity, and has Rainbow Dash. There is no crackshipping involved, beyond your personal attempt to label “ships I dislike are crackships.”
 
Again, you’re welcome to your “sister swap” symmetry. I think it’s far more interesting to explore the actual ships involved. I don’t see anything interesting shipping Applejack with either Sweetie Belle or Scootaloo. I think the two ships in the picture are fine. And I think Twilight and Apple Bloom would make a similarly cute, if unconventional ship.
 

>tfw never hugging a cute girl an entire foot taller than you, while hiding under their sleeping bag with them
 
God I wish I was Sweetie B

This is promising.

@Background Pony #B05B  
AJ gets Spike then, that good enough?

@Background Pony #B05B  

 
But it’s far more logical than your nonsensical crack shipping since this is an already established sister-swap style ship.

@Background Pony #B05B  
Because they’d actually get along well and create an interesting pairing.
 
Your effort to involve only “sisters” only satisfies your sense of symmetry.

@Cryosite  

 
Why? Twilight has no younger sister.  
The 6 I mentioned basically had a sister-figure in their lives, biological or not.

@Background Pony #B05B  
Apple Bloom should hook up with Twilight.

I really love these ships. But I think AJ and Apple Bloom need to get in on the action by a slight shifting of which gal goes to who. RD + SB is fine, Rarity + Apple Bloom, then AJ + Scootaloo. All 6 girls win and any form of (pseudo) incest is avoided if one wants to avoid it. Can even rotate to RD + Apple Bloom, Rarity + Scootaloo, and AJ + SB.

@Cyborg_pony
 
YOU DECIDE

Is this lewd, or are they just hiding from Apple Blooms ghost story last night?

Now. Let me tell you a scary story:  
I was the #0ED2 who commented on  

This image is blocked by your current filter - click here to display it anyway

your current filter.

 
and in the back off my mind while it was going through all the dirty routes, I thought: how about a sister swap…(me always considering Scoots as RD’s little sister, go figure)  
And just moments later this