Artwork by Mavis: http://www.mydirtydrawings.com/
This isn't exactly how I wanted the image to turn out, but I'll just go ahead and post it here. Mavis was only available at unusual hours and that didn't really work out for me, so I was only able to tell him to correct a few things, and some of those ended up worse than they were to begin with.
In the end, it does sorta work as a concept/placeholder.
What I REALLY wanted was Sienna to be looking like she just wants to talk, but having an exasperated look as Kendra just seems more interested in wanting to molest her.
What we ended up with is quite different. Sienna is portrayed as more accepting and into it. Her pose further feeds into that idea.
Some other things that went wrong: Kendra's face. Too much teeth showing? I told Mavis to make her prettier, as I could not pinpoint specifically what was wrong with her face, but it only helped a little. I wanted it look like she's biting her lip, but it just looks derpy.
Both of Sienna's legs were out/straight. I made the mistake of telling him I wanted the bottom of her leg turned up toward her butt. Unfortunately I neglected to say WHICH leg. Doh!
Unfortunately I was not around to tell him what to do with Sienna's wings and her hand placement. At any rate, you can see that it simply doesn't look right. Either her wings should have been more clothlike/limp and/or the hand shouldn't be on it.
The things I do like about it are Sienna's face (despite it not being the right expression, I do think it's cute) and Kendra's breasts. I wish the same level of quality could have been applied to the rest of this piece.
I really should have invested more time in locating better reference images for this, so I am partly to blame.
Another factor is that Mavis seems to have a tooth ache, so kudos to him for even being able to draw.