If you find yourself with a disruptive guest or someone who is not supposed to be there, feel free to remove them from the space.
One of your powers as a host is that you have the ability to remove unwanted guests from your event.
By clicking on the "Event info" button, you will find a window that looks like this:
By clicking on the three dots by an attendee's name, you will see the option to remove that guest.
By clicking the "Remove" button, you will get rid of your unwanted guest. They will not be able to re-enter the event.