There are mountains of jaggies in here. You might wanna take a look at that. Looks like you drew this with a tablet and didn't refine anything on the pixel level. 

 Thanks for the CC. I might give the WIP forum a visit :)

I really like the pose, and the style is quite interesting. The only thing that bothers me a little is the light source, the highlights are kind of inconsistant. The edge of the table is brighter than the top, which indicates the light source is near waist level, yet the tops of their heads are highlighted. Something to think about 
By no means does this mak eit a bad piece, I would suggest submitting it to the WIP forum and get some more opinions if your still not happy about it.