Not sure where this falls, so parts of this request will be spoiler-tagged, just because better safe than sorry. (i.e., better to spoiler something unnecessarily than to leave something unspoilered that should have been.
Universe: Equestria Girls
Setting: Sleepover, currently in a large room.
Characters: Applejack, Fluttershy, Indigo Zap, Lemon Zest, Pinkie Pie, Rainbow Dash, Rarity, Sour Sweet, Sugarcoat, Sunny Flare, Sunset Shimmer, Twilight Sparkle (human)
Attire: All characters are wearing sleepwear, but instead of those sets we saw in Rainbow Rocks and on the cover of Twilight’s Sparkly Sleepover Surprise, all sleepwear tops leave their wearers’ midriffs and underarms bare, and shoulders practically so, while covering the breasts and most of the back. Bottoms may be short, medium, or long, but they must be there, and be opaque.
Activity: All twelve girls are either tickling another girl or being tickled. I’ve assigned the following pretty much randomly:
Sugarcoat tickles Lemon Zest’s underarms
Pinkie Pie tickles Twilight Sparkle’s bellybutton
Sunny Flare and Rarity tickle each other’s ribs
Fluttershy tickles Rainbow Dash and Indigo Zap on their tummies
Sunset Shimmer and Sour Sweet tickle Applejack, each taking a foot
…so you can swap these around if you really want, but I’d prefer you at least leave the structure of each tickle group intact, as well as represent all of those tickle spots without adding more risqué ones.
This will probably end up being a fairly big picture to get all of that in.