So much that he does is 'for his nephew' yet we hear absolutely nothing about his nephew. Where's all the stories about the funny/new thing he said today, or freaking out because he can't leave the house without a specific toy, or wanting to watch caillou on repeat?
Things Lou has actually said about his nephew and not just used him as an excuse for something:
He once wrote Lou successfully
He goes to school, part time I think?
He might like the sonic movie. Probably does, but this was just Lou saying he spent money on him so who knows.
Lou seems to know next to nothing about his nephew firsthand despite taking such a huge role in his financial and physical care. Or he cares too little to share like he does about everything else. Probably both.