I don't know your family but my suggestion would be that you treat the rest of them nicely and inclusively, and continue to try to invite him to appropriate family functions, for example if you have a Sunday dinner or something of that nature. Otherwise, just let him be. He is being inappropriate and controlling of you.

If your family brings the matter up I would just say, "you know, Uncle John and I are both grown men and I've made clear to him that I'd like to work things out. It's up to him if he wants to or not. In the meantime, I'd rather the damage between he and I not impact your relationships with either of us...we both love you, and there's no sense in making things worse than they are."

Do not discuss all the details, and if pressed, just say, "Uncle John isn't here and I don't feel right discussing this matter behind his back, so let's talk about something else, please." Or if it would go over better, just listen respectfully and say, "I will consider what you've said but ultimately, we are both adults and I hope you will respect that he and I need to work this out directly - it's not really a matter for the entire family to worry about."

Best wishes to you.