Hope you guys have a great time....sounds like a top trip.
Tom, whats a day or two of school in the long run, share the memories with your son on the trip...have a good time together and I'm sure he'll remember that a lot more fondly than a school class.....lol. Good on ya for putting him first in your life.
Don't know whats going on with his mother....my girlfriend has two boys and they are the number 1 thing in her life...ahead of me, totally understandable and I love and respect her for that.....I don't think I'd want to be with someone who'd so lightly "ditch" their child.