I can't say I agree with the parents but if they wanted the "urban, cool, and tough guy look" then you did a very good job giving it to them. I for one don't agree with re-cropping. In a shot like this it's the look that's important and re-cropping would not change anything but would tend to diminish the effect by making the faces smaller. Sometimes it's OK to break the rules, cut off ears, fingers and even top of heads to achieve the effect you are looking for. When it comes down to it, all photos are subject to the ultimate final rule, "Do you like it", in this case the parents, yes, then it's a good one.