An excellent question. Is the boy neutered?

I am assuming from your post that you are a woman, is that correct? If it is, you're just going to have to assume the role of the alpha bitch. Growling at him when he is doing wrong and crating for it are possible "consequences" for marking. There are the things you can put around him that prevent him peeing--sort of like the pads for females in heat.

I assumed you're a woman because you said Eddy minded your son pretty well. Men have the deeper voice and more "overbearing" stance that mark an alpha dog. You need to adopt some of that for your own dealings with Eddy. Take the voice from the diaphragm--almost like a karate yell. Firm and steady with a deeper tone.

Nature's Miracle and Simple Solution are both great for getting the scent he's leaving out. Don't use carpet or furniture cleaners with ammonia in them. Guess what he'll smell the next time??

It might also be worthwhile to get baby gates and limit his access to various parts of the house. Places you can keep an eye on him in.

Please keep us posted as to how he progresses.

Chris