daer Amy,flight attendants are quite discreet and although i have never been on a long haul flight the longest being 2.1/2 hrs im sure if you have a word with the steward that your kids wear protection and may go into the toilet to put their protection and that the bag they are carrying is not a bomb just protective wear Im sure that they will understand as Im sure the airline would rather a child wear protection rather than wetting their seats! ...lol so dont worry about it just be discreet with the stewardess or steward!. hope this is of help Tom.UK