I love these pictures of yours. The simplicity of the black and white with a hint of other colour gives it a personality which makes it easy to identify as yours.
I also love that the details haven't been sacrificed because of the black and white nature of the image.
The only things that stand out to me would be the navel to groin proportion being off. As a result the legs seems a little disjointed. To be fair though, I actually had to really stop and think about what was catching my eye about that.
The hand is also a little confusing though I'm not sure I could really pin down what I might suggest.
Now all that being said, I LOVE how you did his hair! I can't say enough how well you do with the light/dark balance.