Hey Irishboy, btw, your " I figured I should go along on this one ... " was the only reason I made that first response to FT in 3 yrs; it's wonderful;
So along those lines (before your youngest catches on.. hopefully not before he's 25) might I suggest a coupla of other (ahem, necessary) chareroned itineraries to spend with your boys? DEF Capetown: the peninsula, great winelands, a safari, ?great-white cage dive; Jordan: Amman, Petra, etc, etc; Cambodia: Angkor, etc, etc; (if you are a really good sell b/c it is SO safe/amazing) Lisbon...
or Madrid or Barcelona) Oh, Peru and Macchu??!! ..etc, etc, etc (Hey, even Guat: Antigua, Atitlan, Tikal: A.m.azing!!) I wish you all the best.