Hi there Beachtime
I want to save the relationship so badly
I’m just so very sorry to read your post. You obviously love your son very much and he’s very luck to have you.
I have an adult son who is now 30. He sounds very similar to you son at the same age in that he’s a charmer, good looking and doesn’t always make good choices.
It’s great your son has asked to stay with you over the holidays. Presumably he could have made arrangements, but he chose to stay with you instead. This must warm your heart but I can understand the anxiety that brings. Christmas is always tricky for us as a family! I guess it is for all of us on this forum.
This is an opportunity for you all to somehow reconnect, but even if that doesn’t happen in any big way...a calm and mutually respectful Christmas surely would be a good thing. I don’t think we can go far wrong by being warm hearted, non-judgmental and relaxed with our adult children. They in turn may demonstrate these behaviours back. Sometimes we have a good day, sometimes less so. If my son struggles on a visit over the holidays ...it’s easier for him to leave (with a smile and big hug from me) and of course this gives us the breathing space to recover back to a happier rhythm in our house for the holidays, Our enjoyment should not fully depend on him. We can choose to not dance to his negative rhythm.
While your son stays with you, it’s only natural he’ll want to see his friends and maybe their families. Your son is young and will naturally want to socialise, particularly because he has a girlfriend. My son never chose to have his friends over while we were around, he likes to compartmentalise all his relationships. I try to not take it personally and, with practise, I’m not so hurt by it any more.
The Christmas aspect is a separate issue to “saving” your relationship. Christmas is only a few days. Saving a relationship is not possible if it’s only a one-sided attempt ...I say this gently...a better word is “healthier” relationship.
You and your husband can strive for a healthier relationship with your son. It takes a lifetime, as I’m discovering. For me, I made this my goal. It’s a bit up and down, but there’s progress.
I suggest you reduce down your wishes/hopes to something more manageable. A focus on you all having a “healthier relationship” over Christmas, even if you only manage a small part of the holidays, it’s something that can be built upon in the future.
Your son may arrive feeling anxious. Even just the warm welcome you give him can be celebrated. ... It’s also something that can be happily remembered by both him and you. The small things are really important to those sensitive ones. If you try to be more thoughtful, don’t ask too many questions they may relax and be able to behave more like themselves (while respecting your boundaries). My son is quite resentful we don’t allow him to smoke weed in our house, but he accepts it.
It’s all about expectations - it’s best to not have any. At one point in our journey, I was just happy to have my son in the room, “not so bad a time ” was an achievement. Slowly, over the last 6 xmases, we build a bigger picture but it’s made up of literally thousands of baby steps...some backwards but mostly forwards,
So, best to have no expectations of “saving” anything. Just be happy as you can be. Hopefully, you’ll witness or feel tiny bits of reconnection here and there, like twinkle dust.

Good luck
LP