[33girl]

You CANNOT make any event mandatory that has alcohol (even if it's a 3rd party serving it) - at least that's what I've been told.

I have heard of not being allowed to go to the mixer if you miss this or that - however, this is something the whole chapter should have voted on. Ditto the arriving and leaving times if the mixer is alcohol free.

If it's a thing that required a bus to get there, I can understand it, but it doesn't sound like this is what's going on. The only "safety" issue that should come up is making sure no one drives drunk or drinks underage.

Contact the regional person who oversees your collegiate chapter (whatever she's called) and let her know this is happening.