First of all let me say that this is SUPER clean as far as lines and paint go. Great job there.
For me the problem is essentially twofold: (a) I don't find her that sexy; and, (b) I don't follow the story provided the visual cues I'm given. On (a), she's very much a male anatomically (shoulders are bigger than the hip-pelvis spread, especially if we turned her in perspective to be right side up). On (b), she doesn't look happy at all to receive this dick. Yet, if she doesn't look happy why is *she* pulling the leg up for this dick? I guess you could have explored the rea*** for the angry face a bit more by attaching something else to that floating dick there?
But ultimately I'm impressed with your crisp lines and paint. You've got that down, so, tell a different story with it and let this one go!