nudes Lo Key

I am sorry to have to say this but this is not a low-key image but is underexposed by almost 3 stops.  There is a difference.  A low key image has the majority of its tones in the darker shades but does have some in the brighter ones.  Look at the histogram of this image in Photoshop and you will see that there are no pixels on the right side.

Jerry Matchett

Jerry is right.  Here it is punched up.

and many thanks for the honest critic - no need to feel sorry.

What you also see in the punched up version is that it becomes simply blown out....

I also tend to disagree that a low key needs to have highlights... doesm't it also depend on the scene?

Well, for me personally Andreas, leaving an image underexposed such as this one (and I've done it too!) leaves me feeling as though it is milky and cloudy... just begging for some contrast and brightness.

Once brought to an acceptable curve however, one could always go in with some burning and dodging to improve any specific areas. 

I guess the bottom line is, you're the photographer, and if this presentation is what you envisioned, the first person you have to please is yourself.