"Oh, what a tangled web we weave when first we practice to deceive." - Sir Walter Scott
How you want to handle this really depends on the *type* of stbx that you're dealing with, imo. If you having the kids 3 weekends in a row means that they won't get to see dad for a month, it might be considerate for you to offer him a dinner or a weekend afternoon or something. But that may end up biting you in the ass if you have a stbx who takes 5 miles for every 1 inch that you give.
Like CG said, holiday time *trumps* regular visitation. And I think it's unusual for a make-up provision to be automatically included. I think the assumption is that, in the end, the *time* will end up being a 'wash'. (maybe next year Easter is *his* and falls on *your* weekend or he'll have them on "Flag Day" this year even though it's technically supposed to be *your* day, kwim?)
But it's really a moot point until and unless your stbx actually brings it up to you as an issue. He can't point a finger at you and call you unfair or unreasonable if he never raised the issue in the first place. Well, he could try, but he'd have no credibility.
In my effort to be *concise*, I often come off as blunt and harsh. Sorry, don't mean to be offensive.