I think the easiest way to deal with your time in Orlando is to hand him a detailed itinerary NOW - park plans and ADRs. Tell him this is what your family is doing and he is welcome to join you if he wants. Or, outline what parts of those days he is welcome to join - one meal a day, or one park day all together. Create the plan with your DH and present it to him together.
The worst thing you can do is be passive aggressive and complain that he is changing the vacation. Tell him what he can join. If he complains, remind him that he's the tag-a-long, not the focus. Be assertive and in control of your plans. Make sure your DH is on board for this, too. If I was your kids and I saw another relative (no matter who) change the trip so I couldn't see and do what I wanted to, I'd be annoyed with you for giving in. Don't.
I agree, though, that you can't tell him stay away without a fight two months later. The time to deal with it was then. Would you punish your kids for something they did two months later but felt akward about bringing up before? Make a plan to ensure your family's vacation. If you're the one in control, much of what you don't like about him sounds like it will be under control IF you and your DH don't cave to demands.
The worst thing you can do is be passive aggressive and complain that he is changing the vacation. Tell him what he can join. If he complains, remind him that he's the tag-a-long, not the focus. Be assertive and in control of your plans. Make sure your DH is on board for this, too. If I was your kids and I saw another relative (no matter who) change the trip so I couldn't see and do what I wanted to, I'd be annoyed with you for giving in. Don't.
I agree, though, that you can't tell him stay away without a fight two months later. The time to deal with it was then. Would you punish your kids for something they did two months later but felt akward about bringing up before? Make a plan to ensure your family's vacation. If you're the one in control, much of what you don't like about him sounds like it will be under control IF you and your DH don't cave to demands.