Third wheeling

@Verram I'm sorry you're going through this. It sounds like that while you don't mind his wife or object to her being there, you do miss the old relationship that you had with your friend. Missing that friendship is completely understandable, and I think anyone in your situation would feel a little upset as well.

I know you suggested meeting up with your friend without his wife there, but have you just come out and asked why the sudden change in his behavior? (Side Note!! - I wouldn't start off the conversation asking him "why the sudden change" as this kind of places them in a defensive position. Rather I would phrase it more like, "I FEEL as though there is this sudden change" End side note) I don't know how comfortable you feel opening up with him, but I think a good friend would want to know if their actions were somehow hurting you. What you're asking for isn't unreasonable - you're not asking for him to completely ditch his wife, or even go back to how things were before he was married. What you're asking for is just a small bit of his time, one-one on, like it used to be. If that's not something he feels like he can give you, then it sounds like there are either some time-management skills he needs to improve on, or there may be some some boundary/communication issues going on within his marriage and, in that case, there's not much you can do. That would be up to them to fix it, if they are even able to identify there's a problem in the first place.

Regardless of the outcome, the way I see it, I think you have three options:

1.) You communicate with your friend how you feel

2.) You continue on with your friendship as you have been

3.) You walk away.

If you choose the first option, I would suggest figuring out what your boundaries are as well before you have the conversation. What change would make you happy, and what would you be able to comfortably settle for? Would continuing on as normal, without any change, be truly okay with you? Or would it hurt more to stay as is, than it would to walk away knowing that you tried. It's important that we communicate with ourselves, and not only each other. Because settling as a way to avoid communication, only hurts ourselves and our relationships in the end.

Good luck!