its a balancing act with youngsters on planes - a couple of hours is get away able , but when you are doing overnights and the young people get overtired, you can get into a spiral that seems to have no end. I have done this with a 18 month year old that was ratcheted up to 11 on the red faced tantrum meter. Few parents (if any) structure this kind of event as some kind of loltastic airborne jape. The sour faced couple behind me kicked off a couple of times and I apologised and clarified that this was hardly planned and the kid was shattered. the third time,still seeing we were genuinely struggling to calm the baby down, I told them to fuck off. that shut them up