What is the best way to make an exit only door?

I’m trying to make a door that only opens from one side. The door needs to open multiple (infinite) times, and needs to work in multiplayer. The door is a prop_door_rotating. What is the best way to go about this?

Ideally, a player wanting to go through the doors backwards should have another player open the doors for them. I thought of a trigger that unlocks the door, but all someone would have to do is stand there and someone on the other side could open it for themselves; not 100% ideal.

Use a trigger_multiple that unlocks and opens the door when you enter, and closes and locks it otherwise?

As long as the trigger doesn’t actually go THROUGH the door, people on the oherside wouldn’t be able to trigger it and unlock it.

Should I use Onstarttouch or Onstarttouchall?

Edit: I’m using onstarttouchall

Or else if you have two players opening it, and one leaves, it will lock.