Since everybody's in agreement, I have another scenario: Last day of school, at dismissal, (half day for students), a mother says to a teacher, "You put up with my kid all year, and you definitely deserve this," and hands her a one of those reusable plastic cups with a straw in it. Teacher takes a sip, and it's vodka.
Okay to drink? Students are gone, our rooms are packed, but we are not allowed to leave the building for another 2.5 hours.
I really wouldn't have any problems if the teachers and staff had a little party and had some drinks after the school business was complete. Obviously if this is a dry campus, this would be a no-no. The fact that this teacher took a sip is okay, she had no idea what was in the cup, but at this point she would just need to dump the rest. I think a gift of alcohol would be better in a closed container. I'm going to assume that most school campuses are going to be dry and alcohol is forbidden, so bringing in an open container was probably not the best idea. This parent should be told, thanks, but this is against the rules.