NB: This is not very (read: not) secure. As always, please don't hack the Gibson.
As the host:
tmux -S /tmp/starwars new -s starwars chmod 777 /tmp/starwars
Then wall to let people know it's ready and they can join with:
tmux -S /tmp/starwars attach -t starwars
Once people have joined, start the film:
Enjoy! (It ends pretty early, so don't be disappointed.)
You can clean up afterwards by removing the shared socket: