This is the final.
And a peek at the process. Here's one of the first ideas.
This one was my favorite. It's both erotic and playful. But Aidenke wanted a side view.
So this is a pretty late stage sketch side view. For some reason I've been having a lot of problems with profiles lately, so I changed the seated figure's face quite a lot. The girl on top's face came really quickly though.
At first I started coloring using my standard chalk brushes, but it didn't seem to fit the picture and pencils. The colors ended up looking really messy and too gritty. So I threw them all out and started from scratch with a more comic-book coloring approach. This seemed to work better.