This one is really hard. I totally get it. I think you have to give him some space. He really needs to be able to choose. I feel for him, truly. It is difficult enough growing up these days without having your Mom walk out, your parents fighting and your sisters living elsewhere. No doubt he is torn.
My daughter was 12 when her dad walked. My L and C both told me she was old enough to choose who to live with. She would never have gone with her dad - she has never accepted his OW and won't have her in her life - so that was not the problem. The problem was that she was devastated - just as your son is - and took out all her frustration on me. It was extremely difficult to live with her and it never really got easier.
Daughter had to get her own apt last Spring when I moved away. Our R has never been better as we are now apart. But it took years of strain, understanding, frustration and LOVE.
Your son probably does not know how to handle the situation any differently. Give him some time. I'm sure you can see how that is working with your daughters. Time and space and unconditional love has helped create a new R with them.
Don't worry about the courts. It is what is best for your son that counts. If you fought to have him stay with you against his will - how would that end up in 5 years? And trust me - those 5 years will go by fast.
The part that worries me here is that wife will side with him against you. I think you really need to try to communicate to her from a co-parenting standpoint. And I DO understand how hard that is because my ex was unreasonable and irrational about EVERYTHING to do with our daughter after he left. Luckily - I had sole custody - but still - she is OUR daughter.
So - my best advice is to NOT guilt him into coming home just yet or ask for some time with him. He obviously needs some space for a bit. Just letting him know you're there and the door is open is enough in my opinion.
