My DD went ice skating with her class this afternoon. They ask for parent helpers to get the kids togged out in their skating clothes, in ice skates and helmets. Everyone meets at the rink at 1.30 and they children get on a coach to go back to school at 3.15 so it's a total of one hour and forty five minutes.
AIBU in thinking if you cannot last that long without having a fag in full view of all the kids (twice, and that's in addition to the one she had oitside the rink out of view during the lesson) then you shouldn't volunteer.