My husband and I just returned from Disney World we travel there at least 2 times a year . . .Our kids (20 and 16) stay behind and take care of the babies for us. I can tell you that yes, they'll miss you, BUT, they really don't have any concept of time . . .just like when I go to work each day and then return home, it's like I've been gone forever.
They'll be fine . . .have a GREAT trip!
