There's a lot to like in these images: interesting juxtaposition of textures (smooth skin, rough BG), that are brought together with semi-agonizing/anxious poses in a gritty scene. Good zone variation in the exposures, with highs and lows well-considered and implemented.
I think my favourite (if I ignore my male gaze for a minute) is probably the last photo. The calves are just slightly over-exposed, bringing symmetry with the pattern of the background.
RE: Trying my hand at monochrome art nude photography